JP7006310B2 - Heat exchanger and heat source machine - Google Patents

Description

The present invention relates to a heat exchanger and a heat source machine.

Conventionally, a heat exchanger having a body plate, a heat transfer tube housed in the body plate, and a connection tube connected to the heat transfer tube has been used. The body plate includes a peripheral wall portion and an internal space surrounded by the peripheral wall portion. The heat transfer tube is arranged in the internal space and extends between the side walls of the peripheral wall portion. Further, the heat transfer tube penetrates the body plate and extends to the outside of the body plate. The connecting tube is inserted into the heat transfer tube on the outside of the body plate.

Further, a heat exchanger in which a connecting tube is inserted into a heat transfer tube is described in, for example, Japanese Patent Application Laid-Open No. 2002-254165 (Patent Document 1). In the heat exchanger described in this publication, the heat transfer tube penetrates the plate-shaped end plate. The connecting tube is inserted into the heat transfer tube on the outside of the end plate.

Japanese Patent Application Laid-Open No. 2002-254165

In the above-mentioned conventional heat exchanger, the combustion gas flows in the internal space surrounded by the peripheral wall portion. Therefore, in the heat transfer tube arranged in the internal space, the temperature on the upstream side is higher than the temperature on the downstream side of the combustion gas. Therefore, thermal stress is generated in the heat transfer tube by trying to deform the heat transfer tube so as to protrude from the downstream side to the upstream side of the fuel gas. This thermal stress may cause the heat transfer tube to crack.

Further, even in the heat exchanger described in the above publication, the temperature on the upstream side of the combustion gas is higher than the temperature on the downstream side of the combustion gas in the heat transfer tube. Therefore, thermal stress is generated in the heat transfer tube by trying to deform the heat transfer tube so as to protrude from the downstream side to the upstream side of the combustion gas. Even in the heat exchanger described in the above publication, the heat transfer tube may be cracked due to this thermal stress.

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 suppressing cracking of a heat transfer tube due to heat stress generated in the heat transfer tube, and a heat source machine provided with the heat exchanger. That is.

The heat exchanger of the present invention includes a body plate, a heat transfer tube, and a connecting tube. The body plate has a peripheral wall portion and an internal space. The interior space is surrounded by a peripheral wall. The heat transfer tube is arranged in the internal space, penetrates the body plate from the internal space, and is fixed to the body plate. The connecting tube is inserted into the heat transfer tube so as to protrude into the internal space from the peripheral wall portion, and is fixed to the heat transfer tube.

According to the present invention, since the connecting tube is inserted into the heat transfer tube so as to protrude from the peripheral wall portion into the internal space, the heat transfer tube and the connecting tube overlap in the internal space. Therefore, the heat transfer tube can be reinforced by the connecting tube in the internal space. As a result, it is possible to prevent the heat transfer tube from cracking due to the thermal stress generated in the heat transfer tube.

In the above heat exchanger, the peripheral wall portion is arranged in the center of the region where the heat transfer tube and the connecting tube overlap. Therefore, the thermal stress generated in the heat transfer tube can be evenly received by sandwiching the peripheral wall portion in the region where the heat transfer tube and the connecting tube overlap. Therefore, it is possible to prevent the thermal stress generated in the heat transfer tube from concentrating on one side of the peripheral wall portion in the region where the heat transfer tube and the connecting tube overlap.

In the above heat exchanger, the size of the heat transfer tube protruding from the peripheral wall portion to the outside of the body plate is larger than the dimension of the connecting tube protruding from the peripheral wall portion into the internal space. Therefore, in order to insert the connecting tube into the heat transfer tube, it becomes easy to process the portion protruding from the peripheral wall portion of the heat transfer tube to the outside of the body plate.

In the above heat exchanger, fins arranged in the internal space are further provided. The heat transfer tube penetrates the fins. The connecting pipe is arranged so as to overlap the fins. The fins tend to extend as the fins are heated by the combustion gas. Therefore, thermal stress due to the fins is generated in the heat transfer tube penetrating the fins. Since the connecting pipe is arranged so as to overlap the fins, the portion of the heat transfer tube that penetrates the fins can be reinforced by the connecting pipe. As a result, it is possible to prevent the heat transfer tube from cracking due to the thermal stress generated in the heat transfer tube by the fins.

In the above heat exchanger, the total thickness of the heat transfer tube and the connecting tube is larger than the thickness of the body plate. The body plate is heated by the combustion gas, and the body plate tends to extend. Therefore, thermal stress due to the body plate is generated in the heat transfer tube penetrating the body plate. Since the total thickness of the heat transfer tube and the connection tube is larger than the body plate thickness, the strength of the overlapping portion of the heat transfer tube and the connection tube can be made larger than the body plate strength. As a result, it is possible to prevent the heat transfer tube from cracking due to the thermal stress generated in the heat transfer tube by the body plate.

The heat source machine of the present invention includes the above heat exchanger and a burner capable of supplying combustion gas to the heat exchanger. According to the heat source machine of the present invention, it is possible to provide a heat source machine provided with a heat exchanger capable of suppressing the occurrence of cracks in the heat transfer tube due to the heat stress generated in the heat transfer tube.

As described above, according to the present invention, it is possible to provide a heat exchanger capable of suppressing the heat transfer tube from being cracked due to the heat stress generated in the heat transfer tube, and a heat source machine provided with the heat exchanger.

It is a figure which shows typically the structure of the heat source machine in one Embodiment of this invention. It is a perspective view schematically showing the structure of the heat exchange apparatus in one Embodiment of this invention. It is a perspective view schematically showing the structure of the heat exchanger in one Embodiment of this invention. It is sectional drawing which follows the IV-IV line of FIG. It is sectional drawing which follows the VV line of FIG. It is a side view which shows roughly the structure of the heat exchanger in one practical form of this invention. 6 is a cross-sectional view taken along the line VII-VII of FIG. It is an enlarged view of the VIII part of FIG. 7. It is sectional drawing which shows schematic structure of the heat exchanger of the modification of the embodiment of this invention, and is the figure which corresponds to FIG. It is sectional drawing which shows schematic structure of the heat exchanger of the comparative example, and is the figure of the part corresponding to FIG. It is an enlarged view of the XI part of FIG.

First, the configuration of the heat source machine 100 according to the embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, the heat source machine 100 of the present embodiment includes an ignition plug 1, a primary heat exchanger (explicit heat recovery heat exchanger) 10, and a secondary heat exchanger (latent heat recovery heat exchanger). Mainly 20, a burner 30, a chamber 31, a blower 32, a duct 33, a venturi 34, an orifice 35, a gas valve 36, a pipe 40, a bypass pipe 41, a three-way valve 42, and a housing 50. Have. The primary heat exchanger 10 and the secondary heat exchanger 20 constitute a heat exchanger 200. All the above-mentioned parts except the housing 50 are arranged inside the housing 50. The above parts are the same as those conventionally known except for the heat exchanger 200.

The fuel gas flows to the venturi 34 through the gas valve 36 and the orifice 35. The mixed gas mixed in the venturi 34 is sent to the blower 32. The blower 32 is for supplying the mixed gas to the burner 30. The blower 32 is connected to the chamber 31, and the chamber 31 is connected to the burner 30. The mixed gas supplied from the blower 32 is sent to the burner 30 through the chamber 31. The burner 30 is for generating a heating gas (combustion gas) supplied to the primary heat exchanger 10. The mixed gas blown out from the burner 30 is ignited by the spark plug 1 and becomes a combustion gas.

The burner 30, the primary heat exchanger 10 and the secondary heat exchanger 20 are connected so that the combustion gas passes through the primary heat exchanger 10 and the secondary heat exchanger 20 in order and exchanges heat with hot water. The burner 30 is arranged on the opposite side of the secondary heat exchanger 20 with respect to the primary heat exchanger 10. The burner 30 is configured to be able to supply combustion gas to the primary heat exchanger 10 and the secondary heat exchanger 20. In the present embodiment, the burner 30 is a back combustion type. The burner 30 may be of a positive combustion method.

A duct 33 is connected to the secondary heat exchanger 20, and the duct 33 extends to the outside of the housing 50. As a result, the combustion gas that has passed through the secondary heat exchanger 20 is discharged to the outside of the housing 50 through the duct 33. The portion of the pipe 40 on the hot water outlet side of the primary heat exchanger 10 and the bypass pipe 41 are connected by a three-way valve 42.

Next, with reference to FIG. 2, the configuration of the heat exchange device 200 used in the heat source machine 100 will be described.

As shown in FIG. 2, the heat exchanger 200 is capable of recovering the sensible heat and latent heat of the combustion gas. The heat exchanger 200 includes a primary heat exchanger 10 for sensible heat recovery and a secondary heat exchanger 20 for latent heat recovery. The primary heat exchanger 10 and the secondary heat exchanger 20 are arranged so as to overlap each other in the first direction D1. The secondary heat exchanger 20 is arranged so as to overlap the primary heat exchanger 10 in the vertical direction (vertical direction) in a state where the heat exchanger 200 is installed. That is, in the state where the heat exchange device 200 is installed, the first direction D1 is in the vertical direction.

Next, the configuration of the primary heat exchanger (heat exchanger) 10 used in the heat source machine 100 will be described with reference to FIGS. 2 to 8.

As shown in FIGS. 2 to 5, the primary heat exchanger 10 includes a water inlet section 10a, a water outlet section 10b, a heat exchange section 11, a body plate 12, a body pipe portion 13, and a header member 14. It is provided with a connecting pipe 15. The water inlet portion 10a is a portion where hot water first enters the primary heat exchanger 10. The water inlet portion 10a is connected to the body pipe portion 13. The water discharge portion 10b is a portion where hot water is finally discharged from the primary heat exchanger 10. The water discharge unit 10b is connected to the heat exchange unit 11 via the connection pipe 15.

The heat exchange unit 11 includes a plurality of fins 11a and a plurality of fin pipes (heat transfer tubes) 11b. Each of the plurality of fins 11a and the plurality of fin pipes 11b may be made of SUS (stainless steel). The heat exchange unit 11 is configured such that combustion gas flows outside the plurality of fins 11a and the plurality of fin pipes 11b, and water flows inside the plurality of fin pipes 11b. The plurality of fins 11a are laminated with each other. The plurality of fin pipes 11b penetrate the plurality of fins 11a in the stacking direction. The plurality of fin pipes 11b are arranged in two stages along the first direction D1. In FIGS. 2 to 5 and 7, for convenience of explanation, only a part of the plurality of fins 11a is shown.

The body plate 12 has a peripheral wall portion 121 and an internal space H. The peripheral wall portion 121 has a first end E1 and a second end E2. The second end E2 faces the first end E1. The internal space H is provided so as to penetrate from the first end E1 to the second end E2. An opening provided on the upper side of the body plate 12 is arranged at the first end E1. An opening provided on the lower side of the body plate 12 is arranged at the second end E2. The internal space H is provided so as to connect the opening provided on the upper side of the body plate 12 and the opening provided on the lower side of the body plate 12.

The peripheral wall portion 121 includes a front portion 12a, a pair of side surface portions 12b, and a back surface portion 12c. The front portion 12a, the pair of side surface portions 12b, and the back surface portion 12c form a square frame. The body plate 12 has upper and lower openings. The body plate 12 can supply combustion gas to the inside of the body plate 12 through the upper opening. The body plate 12 can exhaust the combustion gas to the outside of the body plate 12 through the lower opening.

The heat exchange unit 11 is arranged in the internal space H of the body plate 12. The central portion of each of the plurality of fin pipes 11b is arranged inside the body plate 12. Both ends of each of the plurality of fin pipes 11b are arranged on the outside of the body plate 12. The plurality of fins 11a are arranged inside the body plate 12.

The body pipe portion 13 is for cooling the body plate 12. The body pipe portion 13 is arranged along the inner side surface of the pair of side surface portions 12b and the back surface portion 12c of the body plate 12. The body pipe portion 13 includes a first cooling pipe 131, a second cooling pipe 132, and a third cooling pipe 133. The first cooling pipe 131, the second cooling pipe 132, and the third cooling pipe 133 are installed side by side in the first direction D1. The first cooling pipe 131, the second cooling pipe 132, and the third cooling pipe 133 are connected in series via the header member 14. The header member 14 is attached to the front surface portion 12a of the body plate 12. The header member 14 includes a first header member 141 and a second header member 142.

One end of the first cooling pipe 131 is connected to the water inlet portion 10a, and the other end of the first cooling pipe 131 is connected to the first header member 141. One end of the second cooling pipe 132 is connected to the first header member 141, and the other end of the second cooling pipe 132 is connected to the second header member 142. One end of the third cooling pipe 133 is connected to the second header member 142, and the other end of the third cooling pipe 133 is connected to the connecting pipe 15 arranged at the uppermost position. Further, the plurality of fin pipes 11b of the heat exchange unit 11 are connected to each other in series by the connecting pipe 15.

As shown in FIGS. 6 to 8, the fin pipe 11b is arranged in the internal space H. The fin pipe 11b penetrates the body plate 12 from the internal space H. In the present embodiment, the fin pipe 11b penetrates the peripheral wall portion 121 from the internal space H toward the outside of the body plate 12 so as to protrude from the peripheral wall portion 121 to the outside of the body plate 12. The fin pipe 11b is inserted into a hole provided on the outer periphery of the peripheral wall portion 121. Specifically, the fin pipe 11b is inserted into the holes provided in the front portion 12a and the back portion 12c. The fin pipe 11b extends between the front portion 12a and the back portion 12c. The fin pipe 11b extends in the second direction D2 where the front portion 12a and the back portion 12c face each other. The plurality of fin pipes 11b arranged in the same stage are arranged side by side in the third direction D3 in which the pair of side surface portions 12b face each other. The first direction D1, the second direction D2, and the third direction D3 intersect each other. The fin pipe 11b is fixed to the body plate 12. The fin pipe 11b is fixed to the body plate 12 by, for example, brazing.

The connecting pipe 15 is inserted into the fin pipe 11b so as to protrude from the peripheral wall portion 121 into the internal space H. In the present embodiment, the connecting pipe 15 is inserted into the fin pipe 11b from the outside of the body plate 12 toward the inside of the internal space H so as to protrude from the peripheral wall portion 121 into the internal space H. The connecting pipe 15 is fixed to the fin pipe 11b. The connecting pipe 15 is internally fitted in the fin pipe 11b. The connection pipe 15 includes a bend pipe that connects the two fin pipes 11b to each other, and a water discharge pipe that connects the fin pipe 11b and the water discharge portion 10b.

The connecting pipe 15 is inserted into the fin pipe 11b in the second direction D2. The peripheral wall portion 121 is arranged in the center of the region where the fin pipe 11b and the connecting pipe 15 overlap. That is, in the direction in which the connecting pipe 15 is inserted into the fin pipe 11b, the peripheral wall portion 121 is arranged in the center of the region where the fin pipe 11b and the connecting pipe 15 overlap. That is, the peripheral wall portion 121 is arranged at the center between the end portion of the fin pipe 11b protruding to the outside of the body plate 12 and the end portion inserted into the internal space H of the connecting pipe 15. Therefore, in the direction in which the connecting pipe 15 is inserted into the fin pipe 11b, the dimension R1 of the fin pipe 11b protruding from the peripheral wall portion 121 to the outside of the body plate 12 is the connecting pipe 15 protruding from the peripheral wall portion 121 into the internal space H. Is equal to the dimension R2 of. The peripheral wall portion 121 may be arranged so as to include the center of the region where the fin pipe 11b and the connecting pipe 15 overlap in the direction in which the connecting pipe 15 is inserted into the fin pipe 11b.

The connecting pipe 15 is arranged so as to overlap the fins 11a. The connecting pipe 15 is inserted into the hole of the fin 11a through which the fin pipe 11b penetrates. In the present embodiment, the connecting pipe 15 is arranged so as to overlap the fins 11a arranged on the outermost side of the plurality of fins 11a.

The total thickness of the thickness of the fin pipe 11b and the thickness of the connecting pipe 15 is larger than the thickness of the body plate 12. The thickness of the fin pipe 11b is, for example, 0.8 mm. The thickness of the connecting pipe 15 is, for example, 0.8 mm. The thickness of the body plate 12 is, for example, 0.8 mm.

The front portion 12a and the back portion 12c form the first side surface. The pair of side surface portions 12b constitutes the second side surface. The second side surface (pair of side surface portions 12b) intersects the first side surface (front surface portion 12a and back surface portion 12c). The fin pipe 11b is fixed to the first side surface (front portion 12a and back portion 12c). The second side surface (pair of side surface portions 12b) is arranged along the fin pipe 11b. Since the fin pipe 11b is not fixed to the second side surface (pair of side surface portions) 12b, the temperature is higher than that of the first side surface (front surface portion 12a and back surface portion 12c) to which the fin pipe 11b is fixed. Therefore, the body plate 12 tends to be deformed so that the second side surfaces (a pair of side surface portions 12b) bend in the opposite directions. As a result, thermal stress acts on the fin pipe 11b.

In the above, for all the fin pipes 11b, the connecting pipe 15 is inserted into the fin pipe 11b so as to protrude from the peripheral wall portion 121 into the internal space H. However, for at least one fin pipe 11b, the connecting pipe 15 may be inserted into the fin pipe 11b so as to protrude from the peripheral wall portion 121 into the internal space H. In this case, the connecting pipe 15 may be inserted so as to protrude from the peripheral wall portion 121 into the internal space H only with respect to the fin pipe 11b to which the most thermal stress is applied.

Next, with reference to FIG. 9, the primary heat exchanger 10 as a modification of the present embodiment will be described. As shown in FIG. 9, in the primary heat exchanger 10 of the modified example of the present embodiment, the dimension R1 of the fin pipe 11b protruding from the peripheral wall portion 121 to the outside of the body plate 12 is the internal space H from the peripheral wall portion 121. It is larger than the dimension R2 of the connecting pipe 15 protruding inward.

Next, with reference to FIG. 2 again, the flow of combustion gas and water flowing through the primary heat exchanger 10 and the secondary heat exchanger 20 will be described.

First, the flow of the combustion gas flowing through the primary heat exchanger 10 and the secondary heat exchanger 20 will be described. Combustion gas is supplied to the primary heat exchanger 10 through the upper opening of the primary heat exchanger 10. The combustion gas supplied to the primary heat exchanger 10 flows downward from above toward the opening provided on the lower side of the body plate 12. At this time, heat exchange is performed between the combustion gas flowing outside the body pipe portion 13 and the water flowing inside the body pipe portion 13. Further, heat exchange is performed between the combustion gas flowing outside the plurality of fins 11a and the plurality of fin pipes 11b of the heat exchange unit 11 and the water flowing inside the plurality of fin pipes 11b.

The combustion gas that has passed through the primary heat exchanger 10 passes through the opening provided on the lower side of the body plate 12 and the opening provided on the upper side of the body plate 22 of the secondary heat exchanger 20 to pass through the secondary heat exchanger 20. Is supplied with air. The combustion gas supplied to the secondary heat exchanger 20 flows from above to below toward the opening provided on the lower side of the body plate 22. At this time, in the secondary heat exchanger 20, heat exchange is performed between the combustion gas flowing outside the heat transfer tube (not shown) and the water flowing inside the heat transfer tube.

Subsequently, the flow of water flowing through the primary heat exchanger 10 and the secondary heat exchanger 20 will be described. The water flowing into the secondary heat exchanger 20 from the water inlet portion 20a of the secondary heat exchanger 20 is heat-exchanged with the combustion gas in the secondary heat exchanger 20 and then discharged from the water outlet portion 20b. The water discharged from the water outlet portion 20b of the secondary heat exchanger 20 enters the water inlet portion 10a of the primary heat exchanger 10 via a pipe (not shown).

The hot water that has entered the primary heat exchanger 10 from the water inlet portion 10a flows into the first cooling pipe 131 arranged at the uppermost part of the body pipe portion 13. The hot water that has flowed into the first cooling pipe 131 passes through the first cooling pipe 131, passes through the first header member 141, and flows into the second cooling pipe 132 arranged below the first cooling pipe 131. .. The hot water that has flowed into the second cooling pipe 132 passes through the second cooling pipe 132, passes through the second header member 142, and flows into the third cooling pipe 133 arranged below the second cooling pipe 132. .. The hot water that has flowed into the third cooling pipe 133 passes through the third cooling pipe 133 and flows into the connecting pipe 15 arranged at the uppermost position. The hot water flowing into the connecting pipe 15 arranged at the uppermost position is a series of water passages in which a plurality of fin pipes 11b and a plurality of connecting pipes 15 are connected in series in a direction in which the front portion 12a and the back portion 12c face each other. It flows so as to fold back in (second direction D2). Finally, the hot water is discharged from the water discharge unit 10b.

Next, the action and effect of the present embodiment will be described in comparison with the comparative example.
With reference to FIGS. 10 and 11, the primary heat exchanger 10 of the comparative example is different from the primary heat exchanger 10 of the present embodiment in that the connecting pipe 15 does not protrude from the peripheral wall portion 121 into the internal space H. There is. In the primary heat exchanger 10 of the comparative example, when the combustion gas flows from the first end E1 to the second end E2 of the peripheral wall portion 121, the internal space H is arranged in the internal space H provided in the peripheral wall portion 121. In the fin pipe 11b, the temperature on the upstream side (first end side) is higher than the temperature on the downstream side (second end side) of the combustion gas. Therefore, thermal stress is generated in the fin pipe 11b by trying to deform the fin pipe 11b so as to protrude from the downstream side to the upstream side of the combustion gas. Due to this thermal stress, the fin pipe 11b may be cracked at the position indicated by the arrow in FIG.

On the other hand, according to the primary heat exchanger 10 of the present embodiment, since the connecting pipe 15 is inserted into the fin pipe 11b so as to protrude from the peripheral wall portion 121 into the internal space H, the fins are inserted in the internal space H. The pipe 11b and the connecting pipe 15 overlap each other. Therefore, the fin pipe 11b can be reinforced by the connecting pipe 15 in the internal space H. As a result, it is possible to prevent the fin pipe 11b from cracking due to the thermal stress generated in the fin pipe 11b.

Further, in the primary heat exchanger 10 of the present embodiment, the peripheral wall portion 121 is arranged in the center of the region where the fin pipe 11b and the connecting pipe 15 overlap. Therefore, the thermal stress generated in the fin pipe 11b can be evenly received by sandwiching the peripheral wall portion 121 in the region where the fin pipe 11b and the connecting pipe 15 overlap. Therefore, it is possible to prevent the thermal stress generated in the fin pipe 11b from concentrating on one side of the peripheral wall portion 121 in the region where the fin pipe 11b and the connecting pipe 15 overlap.

Further, in the primary heat exchanger 10 of the present embodiment, the dimension R1 of the fin pipe 11b protruding from the peripheral wall portion 121 to the outside of the body plate 12 is the dimension of the connecting pipe 15 protruding from the peripheral wall portion 121 into the internal space H. Larger than R2. Therefore, in order to insert the connecting pipe 15 into the fin pipe 11b, it becomes easy to process a portion of the fin pipe 11b protruding outward from the peripheral wall portion 121 of the body plate 12.

Further, in the primary heat exchanger 10 of the present embodiment, the connecting pipe 15 is arranged so as to overlap the fins 11a. The fins 11a are heated by the combustion gas, so that the fins 11a tend to extend. Therefore, thermal stress due to the fins 11a is generated in the fin pipe 11b penetrating the fins 11a. Since the connecting pipe 15 is arranged so as to overlap the fin 11a, the portion of the fin pipe 11b that penetrates the fin 11a can be reinforced by the connecting pipe 15. As a result, it is possible to prevent the fin pipe 11b from cracking due to the thermal stress generated in the fin pipe 11b by the fin 11a.

Further, in the primary heat exchanger 10 of the present embodiment, the total thickness of the thickness of the fin pipe 11b and the thickness of the connecting pipe 15 is larger than the thickness of the body plate 12. The body plate 12 is heated by the combustion gas, so that the body plate 12 tends to extend. Therefore, thermal stress due to the body plate 12 is generated in the fin pipe 11b penetrating the body plate 12. Since the total thickness of the thickness of the fin pipe 11b and the thickness of the connecting pipe 15 is larger than the thickness of the body plate 12, the strength of the portion where the fin pipe 11b and the connecting pipe 15 overlap is larger than the strength of the body plate 12. Can be done. As a result, it is possible to prevent the fin pipe 11b from cracking due to the thermal stress generated in the fin pipe 11b by the body plate 12.

Further, in the primary heat exchanger 10 of the present embodiment, the second side surface (pair of side surface portions 12b) intersecting the pair of first side surfaces (front surface portion 12a and back surface portion 12c) to which the fin pipe 11b is fixed is. It is arranged along the fin pipe 11b. The temperature of the pair of second side surfaces to which the fin pipe 11b is not fixed is higher than the temperature of the pair of first side surfaces to which the fin pipe 11b is fixed. Therefore, the body plate 12 tends to be deformed so that the second side surfaces (a pair of side surface portions 12b) bend in the opposite directions. As a result, thermal stress acts on the fin pipe 11b. In the present embodiment, since the fin pipe 11b can be reinforced by the connecting pipe 15 in the internal space H, it is possible to prevent the fin pipe 11b from cracking due to this thermal stress.

The heat source machine 100 of the present embodiment includes the above-mentioned primary heat exchanger 10 and a burner 30 capable of supplying combustion gas to the primary heat exchanger 10. According to the heat source machine 100 of the present embodiment, there is provided a heat source machine 100 provided with a primary heat exchanger 10 capable of suppressing the occurrence of cracks in the fin pipe 11b due to the thermal stress generated in the fin pipe 11b. be able to.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

10 Primary heat exchanger, 11 heat exchange part, 11a fin, 11b fin pipe, 12,22 body plate, 12a front part, 12b side part, 12c back part, 13 body pipe part, 14 header member, 15 connection pipe, 20 Secondary heat exchanger, 30 burner, 100 heat source machine, 121 peripheral wall, 200 heat exchanger, E1 1st end, E2 2nd end, H internal space, R1 heat transfer tube dimensions, R2 connection tube dimensions.

Claims (4)

A body plate having a peripheral wall portion and an internal space surrounded by the peripheral wall portion,
A heat transfer tube arranged in the internal space, penetrating the body plate from the internal space, and fixed to the body plate,
A connection tube inserted into the heat transfer tube and fixed to the heat transfer tube so as to protrude from the peripheral wall portion into the internal space is provided .
A heat exchanger in which the peripheral wall portion is arranged in the center of a region where the heat transfer tube and the connection tube overlap . Further provided with fins arranged in the interior space,
The heat transfer tube penetrates the fin and
The heat exchanger according to claim 1 , wherein the connecting pipe is arranged so as to overlap the fins. The heat exchanger according to claim 1 or 2 , wherein the total thickness of the thickness of the heat transfer tube and the thickness of the connecting tube is larger than the thickness of the body plate. The heat exchanger according to any one of claims 1 to 3 .
A heat source machine provided with a burner capable of supplying combustion gas to the heat exchanger.

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