JP6436197B2 - Heat exchanger and water heater - Google Patents

Description

  The present invention relates to a heat exchanger and a water heater.

  The heat exchanger mainly includes a plurality of plate-shaped fins, a heat transfer pipe penetrating the fins, a water supply pipe and a hot water pipe connected to the heat transfer pipe, and a body plate as an exterior. The water heater has the heat exchanger described above, a burner that generates combustion gas, and a blower unit that sends the combustion gas generated in the burner to the heat exchanger.

  The heat exchanger used for such a water heater is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-227294 (Patent Document 1), Japanese Patent Application Laid-Open No. 61-55595 (Patent Document 2), and the like.

  Japanese Unexamined Patent Publication No. 2000-227294 discloses a plate-like offset fin formed by cutting and raising from a fin. This publication describes that by disposing an offset fin between two heat absorption tubes, the heat quantity of the exhaust flow can be transmitted to the dead angle side in the flow of the exhaust flow of the heat absorption tube, and the heat exchange efficiency can be improved.

  Japanese Laid-Open Patent Publication No. 61-55595 discloses a cut-and-raised portion in which a part of a fin is opened and bent upstream. This publication describes that the heat transfer coefficient behind the cut-and-raised portion can be improved by the vortex generated by the opening of the fin and the unevenness of the upper edge of the cut-and-raised portion.

JP 2000-227294 A JP-A-61-55595

  However, in the heat exchanger described in Japanese Patent Laid-Open No. 2000-227294, there is a problem in that the heat quantity of the combustion gas cannot be sufficiently transmitted to the heat transfer tube in the blind spot region of the exhaust flow (combustion gas flow) of the heat absorption tube (heat transfer tube). is there.

  Further, when the cut-and-raised portion is provided orthogonal to the flow of the combustion gas as disclosed in JP-A-61-55595, it becomes difficult for the combustion gas to pass through the heat exchanger, and the combustion in the heat exchanger Increases gas exhaust resistance. Therefore, when the rotational speed of the blower is increased in order to send the combustion gas to the heat exchanger, there is a problem that noise due to the rotation increases.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to sufficiently transfer the amount of heat of the combustion gas to the heat transfer tube and suppress noise in the blind spot region of the flow of the combustion gas in the heat transfer tube. It is to provide a heat exchanger and water heater that can.

  The heat exchanger of the present invention 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 arranged in a stacked manner at intervals from each other. The heat transfer tube passes through the plurality of through holes of each of the plurality of fins. At least one fin among the plurality of fins includes a cut and raised slit and a cut and raised wall portion. The cut and raised slit is formed in a region adjacent to the first direction of at least one of the plurality of through holes, and has a tunnel-like hole extending in the second direction intersecting the first direction. ing. The cut-and-raised wall portion is located in the second direction of the cut-and-raised slit, protrudes from the main surface of at least one fin, and extends along the first direction. The cut and raised wall portion is disposed only on the downstream side of the cut and raised slit in the flow direction of the combustion gas.

  According to the heat exchanger of the present invention, the cut and raised wall portion extends along the first direction in which the plurality of through holes are arranged. 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. Therefore, the flow of the combustion gas can be guided to the blind spot region of the combustion gas flow in the heat transfer tube, and the heat amount of the combustion gas can be sufficiently transmitted to the heat transfer tube also in the blind spot region.

  The cut and raised wall portion is located in the second direction of the cut and raised slit. For this reason, the combustion gas flowing in the second direction is cut and raised before passing through the cut and raised wall. This cut-and-raised slit has a tunnel-like hole extending in the second direction. Therefore, the combustion gas flowing in the second direction passes through the tunnel-like hole, cuts and rises and collides with the base part of the wall part, and cuts and rises without passing through the tunnel-like hole and the tip part of the wall part It is divided into the flow which collides with. As a result, it is possible to reliably guide the flow that collides with the root side of the cut and raised wall portion of the combustion gas to the blind spot region of the flow of the combustion gas in the heat transfer tube. In addition, since the flow that collides with the front end side of the cut and raised wall portion easily gets over the cut and raised wall portion, the exhaust resistance of the combustion gas in the heat exchanger can be reduced. As a result, it is not necessary to increase the rotational speed of the blower in order to send the combustion gas, so that it is possible to suppress an increase in noise due to an increase in the rotational speed.

  In the above heat exchanger, the cut-and-raised slit and the cut-and-raised wall portion are arranged between the through hole located at the end of the plurality of through holes arranged side by side in the first direction and the edge of the fin. Has been. As a result, the combustion gas flow can be guided to the blind spot region of the combustion gas flow in the heat transfer tube even at the end of the heat exchanger where the combustion gas flow is easy to stagnate. Become.

  In the above heat exchanger, the cut-and-raised slit and the cut-and-raised wall portion are disposed between two through-holes adjacent to each other among the plurality of through-holes arranged side by side in the first direction. As a result, the flow of the combustion gas can be guided to the blind spot region of the heat transfer tube also between two adjacent through holes.

  In the above heat exchanger, the height of the cut-and-raised wall portion from the main surface is larger than half the dimension of the interval between two adjacent fins among the plurality of fins. This makes it possible to more reliably guide the flow of the combustion gas that collides with the base side of the cut and raised wall portion to the dead angle region of the flow of the combustion gas in the heat transfer tube.

  In the above heat exchanger, the length of the cut and raised wall portion extending in the first direction is longer than the length of the cut and raised slit extending in the first direction. As a result, the flow of the combustion gas that has been cut and raised and passed through the slit can be cut and raised and reliably collide with the wall portion.

  In the above heat exchanger, the cut-and-raised wall portion is shifted from the virtual line connecting the centers of the plurality of through holes arranged side by side in the first direction to the downstream side in the combustion gas flow direction. Yes. Thereby, it becomes easier to guide to the blind spot region of the flow of the combustion gas in the heat transfer tube.

  In the above heat exchanger, the plurality of through holes include a plurality of first-stage through holes and a plurality of second-stage through holes. The plurality of first-stage through holes are arranged side by side in the first direction. The plurality of second-stage through holes are arranged side by side in the first direction, and are arranged at intervals in the second direction from the plurality of first-stage through holes. The hole pitch in the plurality of first-stage through holes is smaller than the hole pitch in the plurality of second-stage through holes.

  As a result, each of the plurality of first-stage through holes can be arranged shifted in the first direction with respect to each of the plurality of second-stage through holes. The combustion gas can be efficiently brought into contact with the heat transfer tube passing through the.

  The water heater of the present invention includes any one of the heat exchangers described above and a combustion device for generating combustion gas to be given to the heat exchanger.

  According to the water heater of the present invention, it is possible to sufficiently transfer the heat amount of the combustion gas to the heat transfer tube and suppress noise even in the blind spot region of the flow of the combustion gas in the heat transfer tube.

  The water heater further includes an exhaust collecting cylinder that covers the heat exchanger on the side opposite to the side where the combustion device of the heat exchanger is disposed and has an outlet. A cut-and-raised slit and a cut-and-raised wall are disposed between two adjacent through holes in a region directly below the outlet of the exhaust collecting cylinder, and are adjacent to each other in a region other than immediately below the outlet of the exhaust collecting cylinder. There is no cut-and-raised slit and cut-and-raised wall between the two matching through holes.

  In particular, the combustion gas hardly flows into the blind spot region of the flow of the combustion gas in the heat transfer tube in the region directly below the exhaust port of the exhaust collecting cylinder. For this reason, it is possible to efficiently guide the combustion gas to the blind spot region of the flow of the combustion gas in the heat transfer tube by selectively disposing the cut and raised wall and the cut and raised wall portion in that portion.

  As described above, according to the present invention, it is possible to sufficiently transmit the amount of heat of the combustion gas to the heat transfer tube and suppress noise even in the blind spot region of the heat transfer tube.

It is the schematic which shows the structure of the water heater in one embodiment of this invention. It is a perspective view which shows the structure of the ventilation part, combustion apparatus, primary heat exchanger, and secondary heat exchanger of the water heater in one embodiment of this invention. It is a partially broken perspective view which shows roughly the structure of the primary heat exchanger and secondary heat exchanger of the water heater in one embodiment of this invention. It is a perspective view which shows roughly the structure of the primary heat exchanger of the water heater 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. It is the figure which looked at the primary heat exchanger in one embodiment of this invention from the direction orthogonal to the main surface of a fin. It is a figure which expands and shows a part of FIG. It is a figure for demonstrating that the calorie | heat amount of combustion gas cannot fully be transmitted to a heat exchanger tube in the blind spot area | region RB of a heat exchanger tube in the primary heat exchanger of a 1st comparative example. It is a figure for demonstrating that the calorie | heat amount of a combustion gas can fully be transmitted to the area | region of the blind spot of a heat exchanger tube in the primary heat exchanger in one embodiment of this invention. It is the figure which looked at the primary heat exchanger of the 2nd comparative example from the direction orthogonal to the main surface of a fin. As a third comparative example, it is a cross-sectional view of stacked fins showing the velocity distribution of combustion gas when there is no cut and raised slit and only a cut and raised wall portion is provided. It is the figure of the laminated | stacked fin which shows the velocity distribution of a combustion gas when both the cut-and-raised slit and the cut-and-raised wall part are provided. It is a figure which shows the structure by which the cut-and-raised slit and the cut-and-raised wall part were arrange | positioned only in the area | region right under the exhaust port of an exhaust gas collection cylinder in the primary heat exchanger in one embodiment of this invention. It is the schematic which shows the structure which applied the primary heat exchanger in one embodiment of this invention to the water heater using petroleum as a fuel.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, the structure of the water heater in this embodiment will be described with reference to FIGS.

  With reference to FIG. 1 and FIG. 2, the water heater 1 of the present embodiment mainly includes a housing 2, a combustion device 3, a blower 6, a primary heat exchanger 11, and a secondary heat exchanger 21. Have. The combustion device 3 is for supplying combustion gas. The combustion device 3 includes a burner 3a and a burner case 3b, and the burner 3a is accommodated in the burner case 3b. A gas pipe 5 for supplying fuel gas to the combustion device 3 is connected to the combustion device 3.

  The blower 6 is for supplying combustion air to the combustion device 3 and includes, for example, a fan, a fan case, a fan motor, and the like. The blower 6 is attached to the lower part of the combustion device 3.

  Each of the primary heat exchanger 11 and the secondary heat exchanger 21 is for performing heat exchange with the combustion gas supplied from the combustion device 3. A primary heat exchanger 11 is attached on the combustion device 3, and a secondary heat exchanger 21 is attached on the primary heat exchanger 11.

  The primary heat exchanger 11 and the secondary heat exchanger 21 are connected by a pipe 32. A water supply pipe 31 for supplying water to the secondary heat exchanger 21 is connected to the secondary heat exchanger 21. The primary heat exchanger 11 is connected to a hot water discharge pipe 33 for sending hot water from the primary heat exchanger 11.

  A bypass pipe 35 is connected between the water supply pipe 31 and the hot water pipe 33. The bypass pipe 35 is for adjusting the temperature of hot water fed from the hot water discharge pipe 33 with the water in the water supply pipe 31. In addition, a drain discharge pipe 41 for discharging drain generated in the secondary heat exchanger 21 is provided.

  Referring to FIG. 1 and FIG. 3, the primary heat exchanger 11 includes a plurality of fins 13 stacked on each other, a heat transfer tube 15 penetrating the plurality of fins 13, and a plurality of fins 13 and the heat transfer tubes 15 inside. It has the trunk | drum 17 as a case to accommodate. The heat transfer tube 15 is connected to the pipe 32 at one end and is connected to the hot water discharge pipe 33 at the other end.

  The secondary heat exchanger 21 includes a plurality of (spiral) heat transfer tubes 25 and a case 27 that accommodates the heat transfer tubes 25 therein. The heat transfer pipe 25 is connected to the water supply pipe 31 at one end and is connected to the pipe 32 at the other end.

  The heat exchanger according to the present invention (claims) corresponds to the primary heat exchanger 11 and does not correspond to the secondary heat exchanger 21.

  With reference to FIG. 3, an exhaust collecting cylinder 42 is disposed between the primary heat exchanger 11 and the secondary heat exchanger 21. The exhaust collecting cylinder 42 is formed with an outlet 42 a for supplying the combustion gas having passed through the primary heat exchanger 11 to the secondary heat exchanger 21. The case 27 of the secondary heat exchanger 21 is provided with an exhaust port 27a for exhausting combustion gas.

  Next, the configuration of the primary heat exchanger 11 will be specifically described with reference to FIGS. 4 to 7 and FIG.

  Referring to FIG. 4, each of the plurality of fins 13 stacked on each other is made of a plate-like member, and has a plurality of through holes 13ca and 13cb on the main surface MS of the plate-like member. Each of the plurality of through holes 13ca and 13cb is for passing the heat transfer tube 15 therein. The heat transfer tube 15 is brazed to the periphery of each of the plurality of through holes 13ca and 13cb.

  Referring to FIG. 5, each of the plurality of fins 13 includes a cut and raised wall portion 13a and a cut and raised slit 13b. The cut-and-raised wall portion 13 a is a portion that is cut and raised by cutting out and bending a part of the plate-like fin 13, and is formed integrally with the fin 13.

  The cut-and-raised wall portion 13a has one end portion and the other end portion, the one end portion is a base side connected to the fin 13, and the other end portion protrudes from the main surface MS of the fin 13 It is comprised by bending so that it may become. The bending angle of the cut and raised wall portion 13a with respect to the main surface MS of the fin 13 may be, for example, 90 °, an acute angle, or an obtuse angle.

  The cut and raised slit 13b has, for example, three cut and raised slit portions 13ba, 13bb, and 13bc. Each of the cut-and-raised slit portions 13ba, 13bb, and 13bc is a portion that is cut and raised by cutting out and bending a part of the plate-like fin 13, and is formed integrally with the fin 13.

Each of the cut-and-raised slit portions 13ba, 13bb, 13bc has one end portion and the other end portion, both one end portion and the other end portion are connected to the fin 13, and one end portion and the other end. It protrudes with respect to the main surface MS of the fin 13 by being bent between end portions. Thus cut and raised slit portions 13 ba, 13bb, tunnel-like holes 13ba _1, 13bb _1, 13bc ₁ is formed between one end and the other end portion of each of 13bc.

  The number of cut and raised slit portions included in the cut and raised slit 13b is not limited to three, and may be one, two, or four or more.

  Referring to FIG. 6, the plurality of through holes 13ca and 13cb include a plurality of first-stage through holes 13ca and a plurality of second-stage through holes 13cb. The plurality of first stage through holes 13ca include, for example, four through holes, and the plurality of second stage through holes 13cb include, for example, four through holes.

  The plurality of first-stage through holes 13ca are arranged side by side along the first direction (the arrow DA direction in the drawing) on the main surface MS of the fin 13. Similarly, the plurality of second-stage through holes 13cb are arranged side by side along the first direction (arrow DA direction in the drawing) on the main surface MS of the fin 13. A first stage constituted by a plurality of first-stage through holes 13ca and a second stage constituted by a plurality of second-stage through holes 13cb are in a second direction (arrow in the figure) orthogonal to the first direction. (DB direction) are arranged at intervals. That is, the first stage constituted by the plurality of first-stage through holes 13ca and the second stage constituted by the plurality of second-stage through holes 13cb are arranged in parallel to each other.

  Referring to FIG. 7, the cut and raised slit 13b is formed in a region (hatched region RA in the drawing) adjacent to the first through hole 13ca in the first direction DA. In the present embodiment, all of the three cut and raised slit portions 13ba, 13bb, and 13bc included in the cut and raised slit 13b are arranged in this region RA.

  When the cut-and-raised slit 13b has a plurality of cut-and-raised slit portions, not all of the plurality of cut-and-raised slit portions may be arranged in the region RA, and at least one of the plurality of cut-and-raised slit portions is What is necessary is just to be arrange | positioned in the area | region RA.

  Each of the three cut-and-raised slit portions 13ba, 13bb, 13bc extends in a strip shape from the one end connected to the fin 13 to the other end along the first direction DA. Thereby, each of the tunnel-like holes of the three cut-and-raised slit portions 13ba, 13bb, 13bc extends (penetrates) in the second direction DB.

  The cut-and-raised wall portion 13a is located in the second direction DB of the cut-and-raised slit 13b. Specifically, the cut-and-raised wall portion 13a is located on an extension line in the extending (penetrating) direction of each tunnel-like hole of the cut-and-raised slit portions 13ba, 13bb, and 13bc. The cut-and-raised wall portion 13a is shifted from the virtual straight line CC connecting the centers O of the plurality of first-stage through holes 13ca to the downstream side (secondary heat exchanger side) in the combustion gas flow direction. ing.

  One end portion (root side) connected to the fin 13 of the cut and raised wall portion 13 a extends along the first direction DA on the main surface of the fin 13. Further, the other end portion (front end side) protruding from the main surface of the fin 13 of the cut and raised wall portion 13a also extends along the first direction DA.

  One set of the cut-and-raised wall portion 13a and the cut-and-raised slit 13b has a through-hole 13ca and a fin 13 positioned at the end of the plurality of first-stage through-holes 13ca arranged side by side in the first direction DA. It is arrange | positioned between the edge 13E. Further, the other set of the cut-and-raised wall portion 13a and the cut-and-raised slit 13b is disposed between two adjacent through-holes 13ca among the plurality of first-stage through-holes 13ca arranged in the first direction DA. Has been.

  The length L2 of the cut and raised wall portion 13a extending in the first direction DA has a length equal to or longer than the lengths L1a and L1b of the cut and raised slit portions 13ba, 13bb, and 13bc extending in the first direction. . The length L2 of the cut-and-raised wall portion 13a extending in the first direction DA has a length equal to or less than the hole pitch L3 of the plurality of first-stage through holes 13ca. Further, the length L1b extending in the first direction DA of the cut-and-raised slit portion 13bb at the center has a length equal to or shorter than the length L1a extending in the first direction DA of the cut-and-raised slit portions 13ba and 13bc located on both sides. doing.

  In the present embodiment, among the three cut and raised slit portions 13ba, 13bb and 13bc, the cut and raised slit portion 13bb located at the center is located on a virtual straight line CC passing through the center O of each through hole 13ca. ing.

  Referring to FIG. 12, the height H2 at which the cut-and-raised wall portion 13a protrudes from the main surface MS of the fin 13 is half the dimension H1 of the interval between adjacent fins 13 among the plurality of stacked fins 13 ( H1 × 1/2) and lower than three quarters of the dimension H1 (H1 × 3/4). Further, the protruding height H2 of the cut and raised wall portion 13a is higher than the highest height H3 among the heights of the cut and raised slit 13b (cut and raised slit portions 13ba, 13bb and 13bc) protruding from the main surface MS of the fin 13.

  The distance H1 between the adjacent fins 13 is, for example, 2.5 mm, the protruding height H2 of the cut-and-raised wall 13a is, for example, 1.8 mm, and the maximum protruding height H3 of the cut-and-raised slit 13b is, for example, 1.5 mm.

  Referring to FIG. 6, the hole pitch P2 in the plurality of first-stage through holes 13ca is smaller than the hole pitch P1 in the plurality of second-stage through holes 13cb. For this reason, the center of each of the plurality of first-stage through holes 13ca is shifted from the center of each of the plurality of second-stage through holes 13cb by a predetermined amount G1 to G4 in the first direction DA. .

  The tube diameter of the heat transfer tube 15 is, for example, 16 mmφ, and each of the shift amounts G1 to G4 of the center tube is, for example, 1 mm or more. The total number of the plurality of first-stage through holes 13ca and the plurality of second-stage through holes 13cb is preferably an even number. The number of first-stage through holes 13ca and the number of second-stage through holes 13cb are preferably the same.

Next, operation | movement of the water heater 1 of this Embodiment is demonstrated.
With reference to FIG. 1, when the operation switch is turned on and a predetermined amount of water is caused to flow through the water supply pipe 31, the fan of the blower unit 6 starts rotating, the combustion device 3 is ignited, and the combustion device 3 is directed upward. Combustion gas is sent out. Referring to FIG. 3, the delivered combustion gas flows through the body plate 17 in which the primary heat exchanger 11 is disposed, and then passes through the outlet 42 a of the exhaust collecting cylinder 42 to enter the secondary heat exchanger 21. Then, the air is exhausted from the exhaust port 27a.

  Referring to FIG. 1, on the other hand, water sent from the water supply pipe 31 first flows in the heat transfer pipe 25 of the secondary heat exchanger 21. While flowing through the secondary heat exchanger 21, water is preheated by the combustion gas (latent heat). Next, the preheated water is sent to the primary heat exchanger 11 through the pipe 32. The preheated water sent to the primary heat exchanger 11 flows through the lower heat transfer tube 15 (the heat transfer tube 15 passing through the second through-hole 13cb), and then the upper heat transfer tube 15 (the first heat-passing tube 15). It flows through the heat transfer tube 15) passing through the hole 13ca. While the preheated water flows through the heat transfer tube 15, heat exchange is performed between the combustion gas (sensible heat) flowing through the gaps between the fins 13 and the water in the heat transfer tube 15, and the preheated water is It is heated to a predetermined temperature. Hot water heated to a predetermined temperature is sent out of the water heater 1 through the hot water outlet pipe 33. Thus, hot water having a predetermined temperature can be supplied as the water heater 1.

  Next, the operation and effect of the present embodiment will be described in comparison with the first comparative example shown in FIG. 8, the second comparative example shown in FIG. 10, and the third comparative example shown in FIG.

  In the first comparative example shown in FIG. 8, no cut wall and no cut slit are formed on the main surface MS of the fin 13. In this configuration, it becomes difficult for the combustion gas to flow in the region RB that is the dead angle of the heat transfer tube 15 with respect to the flow of the combustion gas in the second direction (arrow DB direction in the drawing). As a result, in the blind spot region RB of the heat transfer tube 15, the heat quantity of the combustion gas is hardly transmitted to the heat transfer tube 15, and the heat exchange efficiency is deteriorated.

  In contrast, in the present embodiment, as shown in FIG. 9, the cut-and-raised wall portion 13a is provided so as to extend along the first direction (the arrow DA direction in the drawing). For this reason, the combustion gas flowing through the side of the heat transfer tube 15 can collide with the cut and raised wall portion 13a and change the direction of the flow. As a result, the combustion gas can be guided to a region where the heat transfer tube 15 is blind to the flow of the combustion gas, and the heat amount of the combustion gas can be sufficiently transmitted to the heat transfer tube 15 even in the blind region of the heat transfer tube 15. It becomes. This makes it possible to improve the heat exchange efficiency.

  In addition, as in the second comparative example shown in FIG. 10, it is also conceivable to provide two cut-and-raised wall portions 13a extending at different angles with respect to the first direction between the two through holes 13ca. . However, in this configuration, two cut-and-raised wall portions 13a inclined at different angles cannot be connected as one cut-and-raised wall portion due to processing restrictions. For this reason, a gap region where the cut and raised wall portion is not formed is formed between the two cut and raised wall portions 13a inclined at different angles, and the combustion gas flows through the gap region. Therefore, the heat exchange efficiency deteriorates because the amount of heat of the combustion gas flowing through the gap region cannot be transferred to the heat transfer tube 15.

  On the other hand, in the present embodiment, as shown in FIG. 9, one cut-and-raised wall portion 13a extending along the first direction is provided between the two through holes 13ca. For this reason, since the area | region of the clearance gap between the above-mentioned cut-and-raised wall part does not arise, it becomes possible to guide | emit combustion gas to the area | region of the blind spot of the heat exchanger tube 15 efficiently. Therefore, it is possible to improve the heat exchange efficiency.

  Further, as in the third comparative example shown in FIG. 11, it is also conceivable to provide only the cut and raised wall portion 13a without providing the fin 13 with the cut and raised slit. In this case, the flow of the combustion gas that collides with the cut-and-raised wall 13a has a high velocity at the center between the two fins 13 as shown by the curve in the figure, and is small at the end (near the fin 13). Have speed.

  In this way, the flow of the combustion gas in the central portion having a high flow velocity cuts up and collides with the wall portion 13a, and the flow is inhibited. Therefore, the exhaust resistance of the combustion gas increases, and the combustion gas flows from the primary heat exchanger 11. It becomes difficult to exhaust. When the rotational speed of the fan of the blower 6 (FIGS. 1 and 2) is increased in order to promote the exhaust of the combustion gas from the primary heat exchanger 11, noise due to the rotation increases.

  On the other hand, in the present embodiment, as shown in FIG. 9, the cut and raised wall portion 13a is cut and raised and is positioned in the second direction DB of the slit 13b. For this reason, the combustion gas flowing in the second direction DB is cut and raised before reaching the cut and raised wall portion 13a and passes through the slit 13b.

This cut-and-raised slit 13b has a tunnel-like hole 13b ₁ extending in the second direction DB as shown in FIG. Therefore, the combustion gas flowing in the second direction DB passes through the tunnel-shaped hole 13b ₁ , cuts and rises and collides with the base part 13a ₂ side of the wall part 13a, and the tunnel-shaped hole 13b ₁ . The flow is divided into a flow that collides with the tip 13a ₁ side of the wall 13a.

Both the flow which does not pass through here the flow and tunnel-like holes 13b ₁ through the tunnel-shaped opening 13b in _one of the combustion gas between the fins 13 and the cut and raised slits 13b as shown in the figure the curve And has a small speed at the end (near the fin 13 and near the cut-and-raised slit 13b).

Accordingly, the flow of the combustion gas that collides with the root portion 13a ₂ side of the cut-and-raised wall portion 13a has the fastest central portion cut and raised and collides with the wall portion 13a. It is possible to reliably lead to the blind spot area.

On the other hand, the flow that collides with the tip 13a ₁ side of the cut-and-raised wall 13a is easy to get over the wall 13a because the center portion with the fastest flow velocity is cut and raised, thereby reducing the exhaust resistance of the combustion gas in the primary heat exchanger 11 can do. As a result, it is not necessary to increase the rotational speed of the blower 6 in order to send the combustion gas, so that an increase in noise due to an increase in the rotational speed can also be suppressed.

The protruding height H2 of the cut and raised wall portion 13a is lower than three quarters (H1 × 3/4) of the interval H1 between the two fins 13. Therefore, to proceed without colliding earliest central portion cut and raised wall portion 13a of the flow rate of the flow of combustion gases impinging on the tip portion 13a ₁ side of the cut and raised wall portion 13a, to reduce the more exhaust resistance Is possible.

Height H2 of yet cut and raised wall portion 13a of the distal end portion 13a ₁ side switching for the flow of the flow velocity is fastest central portion of the flow of combustion gases impinging does not impinge on cut and raised wall portion 13a to the raised wall section 13a , H2 <H3 + (H1-H3) / 2.

Further, the protruding height H2 of the cut and raised wall portion 13a is higher than half (H1 × 1/2) of the interval H1 between the two fins 13. For this reason, in the flow of the combustion gas that collides with the root portion 13a ₂ side of the cut and raised wall portion 13a, the center portion with the fastest flow velocity is cut and raised and reliably collides with the wall portion 13a. It becomes possible to guide more reliably to the blind spot region of the gas flow.

Note cut and raised height of the cut and raised wall portion 13a of the flow velocity of the flow of combustion gases impinging on the root portion 13a ₂ side flows of the earliest central portion collides reliably the cut and raised wall portion 13a of the wall portion 13a H2 can be obtained by H2> H4 / 2. The height H4 is a height obtained by cutting and raising from the height H3 and reducing the thickness of the slit 13b (that is, the height of the tunnel-like hole 13b _{1 at} the height H3 portion).

  Further, as shown in FIGS. 6 and 7, in the present embodiment, one set of cut and raised slits 13b and cut and raised wall portions 13a are arranged in a plurality of first stages arranged in the first direction DA. It arrange | positions between the through-hole 13ca located in the outermost edge part of the through-hole 13ca, and the edge 13E of the fin 13. As shown in FIG. As a result, the combustion gas flow can be guided to the blind spot region of the combustion gas flow in the heat transfer tube 15 even at the end of the primary heat exchanger 11 where the combustion gas flow is likely to stagnate, thereby suppressing the stagnation of the combustion gas. Is possible.

  As shown in FIGS. 6 and 7, in the present embodiment, a plurality of first-stage penetrations in which another set of cut and raised slits 13b and cut and raised wall portions 13a are arranged in the first direction DA are provided. It arrange | positions between two through-holes 13ca adjacent to each other among the holes 13ca. As a result, the flow of the combustion gas can be guided to the blind spot region of the heat transfer tube 15 between the two through holes 13ca adjacent to each other.

  Further, as shown in FIG. 7, in the present embodiment, the length L2 of the cut and raised wall portion 13a extending in the first direction DA is longer than the lengths L1a and L1b of the cut and raised slit 13b extending in the first direction DA. Also long. As a result, the flow of the combustion gas that has been cut and raised and passed through the slit 13 b can be cut and raised to reliably collide with the wall portion 13 a, and the flow of the combustion gas can be easily guided to the blind spot region of the heat transfer tube 15.

  Further, as shown in FIG. 7, in the present embodiment, the cut-and-raised wall portion 13a is a virtual straight line C connecting the centers O of the plurality of first-stage through holes 13ca arranged in the first direction DA. It is shifted from −C to the downstream side in the flow direction of the combustion gas. Thereby, it becomes easier to guide the flow of the combustion gas to the blind spot region of the heat transfer tube 15.

  As shown in FIG. 6, in the present embodiment, the hole pitch P2 in the plurality of first-stage through holes 13ca is smaller than the hole pitch P1 in the plurality of second-stage through holes 13cb. Thereby, the center of each of the plurality of first-stage through holes 13ca can be shifted from the center of each of the plurality of second-stage through holes 13cb by a predetermined amount G1 to G4 in the first direction DA. . For this reason, a combustion gas can be efficiently made to contact the heat exchanger tube 15 which passes through the inside of each of the plurality of first-stage through holes 13ca.

  In the above embodiment, as shown in FIG. 13, only in the region RC just below the outlet 42a of the exhaust collecting cylinder 42, there is a cut-and-raised slit 13b and a cut-and-raised wall between two adjacent through holes 13ca. The part 13a may be arranged. That is, if the cut-and-raised slit 13b and the cut-and-raised wall portion 13a are arranged only in the region RC, the gap between the two through holes 13ca adjacent to each other in the region other than the region immediately below the outlet 42a of the exhaust collecting cylinder 42 is provided. May not be arranged.

  In the region RC just below the outlet 42a of the exhaust collecting cylinder 42, the combustion gas tends to flow in a straight line toward the outlet 42a. For this reason, the combustion gas is particularly difficult to flow into the blind spot region of the heat transfer tube 15 in the region RC immediately below. Therefore, the combustion gas can be efficiently guided to the blind spot region of the heat transfer tube 15 by selectively cutting and raising the slit 13b and the cut and raised wall portion 13a directly below the region RC.

  In the above-described embodiment, the configuration in which the primary and secondary heat exchangers 11 and 21 are disposed above the combustion device 3 has been described as an example (see FIGS. 1 and 2). The primary heat exchanger 11 of this form may be applied to a water heater that mainly uses petroleum as a fuel. In such a water heater, for example, as shown in FIG. 14, the primary heat exchanger 11 is disposed below the combustion device 3, and the secondary heat exchanger 21 is disposed below the primary heat exchanger 11. become. In this type of combustion system, the blower 6 is disposed above the combustion device, and a fuel pipe 7 is connected to the combustion device 3.

  14 is substantially the same as the configuration of water heater 1 shown in FIG. 1, and therefore the same elements are denoted by the same reference numerals and description thereof will not be repeated.

  In the heat exchanger described above, the arrangement of the heat transfer tubes has been described by taking the two-stage arrangement of the lower stage and the upper stage as an example, but may be arranged in three or more stages. As described above, particularly in the case of the two-stage arrangement, it is possible to contribute to the compactness of the primary heat exchanger. Moreover, the numerical value quoted as a pipe diameter and pitch of a heat exchanger tube is an example, Comprising: It is not limited to this.

  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 Water heater, 2 Housing, 3 Combustion device, 3a burner, 3b Burner case, 5 Gas pipe, 6 Air blower, 7 Fuel pipe, 11 Primary heat exchanger, 13 Fin, 13E Edge, 13a Wall part, 13a ₁ tip Part, 13a ₂ root part, 13b ₁ , 13ba _{1 to} 13bc ₁ tunnel-like hole, 13b cut-and-raised slit, 13ba, 13bb cut-and-raised slit part, 13ca, 13cb through-hole, 15, 25 heat transfer tube, 17 body plate, 21 Secondary heat exchanger, 27 case, 27a exhaust port, 31 water supply pipe, 32 pipe, 33 hot water discharge pipe, 35 bypass pipe, 41 drain discharge pipe, 42 exhaust collecting cylinder, 42a outlet.

Claims (9)

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,
At least one of the plurality of fins is
A cut-and-raised slit having a tunnel-like hole formed in a region adjacent to the first direction of at least one through-hole among the plurality of through-holes and extending in a second direction intersecting the first direction When,
A cut-and-raised wall portion that is located in the second direction of the cut-and-raised slit, protrudes with respect to the main surface of the at least one fin, and extends along the first direction;
The cut and raised wall portion is disposed only on the downstream side of the cut and raised slit in the flow direction of the combustion gas ,
The plurality of through holes are:
A plurality of first-stage through holes arranged side by side in the first direction;
The plurality of first-stage through holes arranged side by side in the first direction include a plurality of second-stage through holes arranged at intervals in the second direction,
The first stage through hole and the second stage through hole are the same number,
The center of each of the plurality of first-stage through holes is arranged to be shifted in the first direction with respect to the center of each of the plurality of second-stage through holes .   The cut-and-raised slit and the cut-and-raised wall portion are arranged between the through hole located at the end of the plurality of through holes arranged side by side in the first direction and the end edge of the fin. The heat exchanger according to claim 1.   The cut and raised slit and the cut and raised wall portion are arranged between two through holes adjacent to each other among the plurality of through holes arranged side by side in the first direction. The described heat exchanger. Height from said main surface of said cut and raised wall portion, the greater than half of a plurality of dimensions of the distance between two of the fins adjacent to each other among the fins, any of claims 1-3 1 The heat exchanger according to item. The length extending in the first direction of the cut and raised wall portion, said longer than the length extending in the first direction of cut and raised slit, heat exchanger according to any one of claims 1-4 . The cut-and-raised wall portion is arranged so as to be shifted downstream from a virtual line connecting the centers of the plurality of through holes arranged side by side in the first direction in the combustion gas flow direction. The heat exchanger according to any one of 1 to 5 . Hole pitch of said plurality of first-stage through holes is smaller than the hole pitch of the plurality of second-stage through holes, the heat exchanger according to claim 1. The heat exchanger according to any one of claims 1 to 7 ,
A water heater comprising: a combustion device for generating combustion gas to be given to the heat exchanger. A heat exchanger ,
A combustion device for generating combustion gas to be given to the heat exchanger,
The heat exchanger is
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 each of the plurality of through holes of each of the plurality of fins,
At least one of the plurality of fins is
A cut-and-raised slit having a tunnel-like hole formed in a region adjacent to the first direction of at least one through-hole among the plurality of through-holes and extending in a second direction intersecting the first direction When,
A cut-and-raised wall portion that is located in the second direction of the cut-and-raised slit, protrudes with respect to the main surface of the at least one fin, and extends along the first direction;
The cut and raised wall portion is disposed only on the downstream side of the cut and raised slit in the flow direction of the combustion gas,
An exhaust collecting cylinder that covers the heat exchanger on the side opposite to the side where the combustion device is disposed of the heat exchanger and has an outlet;
The cut-and-raised slit and the cut-and-raised wall portion are disposed between the two through holes adjacent to each other in the region directly below the outlet of the exhaust collecting cylinder, and just below the outlet of the exhaust collecting cylinder. wall raised the cut and raised slit and the switching is not disposed between two of said through holes adjacent to each other in regions other than the feed water device.

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