JP6865117B2 - Heat exchanger - Google Patents

Description

The present invention relates to a fin tube type heat exchanger used in a one-can two-water channel type combustion device.

Conventionally, in this type of heat exchanger, a hot water supply pipe is arranged on the upstream side and a bath pipe is arranged on the downstream side in the vertical direction to form a pair of pipe groups, and the pair of pipe groups are arranged vertically 2 In a system in which a plurality of fin plates are passed through as a grid-like arrangement of stages to heat the water flowing through each pipe, combustion gas is emitted from the upper edge of the fin plates between each pair of pipe groups in the upper stage. The first notch cut out toward the upstream side in the flow direction and the second notch cut out from the lower edge of the fin plate toward the downstream side in the flow direction of the combustion gas between each pair of pipe groups in the lower stage. In some cases, a notch was provided to disperse the stress applied to the fin plate by the notch. (See, for example, Patent Document 1.)

Japanese Unexamined Patent Publication No. 2000-146307

By the way, in such a heat exchanger, since the temperature of the combustion gas is high on the upstream side in the flow direction of the combustion gas, the amount of heat absorbed by the hot water supply pipe and the bath pipe on the lower stage located on the upstream side in the flow direction of the combustion gas is large. In many cases, the downstream side in the flow direction of the combustion gas flows the combustion gas after the temperature drops due to heat exchange with the water flowing through the hot water supply pipe and the bath pipe on the lower stage, so the upper stage located on the downstream side in the flow direction of the combustion gas. The amount of heat absorbed by the hot water supply pipe and the bath pipe on the side is small, and in addition, the fin plate on the downstream side in the flow direction of the combustion gas is provided with the first notch, so that the fin plate is transmitted. There is a problem that the heat area is reduced, the amount of heat transferred to the hot water supply pipe and the bath pipe on the upper stage side is small, and the amount of heat absorption by the hot water supply pipe and the bath pipe on the upper stage side is small. Regarding hot water supply, since the amount of heat required for hot water supply is large, there is a demand to absorb as much heat as possible from the combustion gas even on the downstream side in the flow direction of the combustion gas, but the upper side located on the downstream side in the flow direction of the combustion gas. No measures have been taken to absorb heat in the hot water supply pipe, and there is room for improvement in increasing the amount of heat absorbed in the upper hot water supply pipe located on the downstream side in the flow direction of the combustion gas, and eventually improving the heat exchange efficiency. there were.

In order to solve the above problems, in particular, in claim 1, a pair of hot water supply pipes are arranged on the upstream side and circulation pipes are arranged on the downstream side in the vertical direction with respect to the flow direction of the combustion gas. In a heat exchanger in which a group of pipes is formed and the pair of pipes are arranged in a grid pattern in two upper and lower stages to penetrate a plurality of fin plates to heat water flowing through each pipe, the pair of adjacent pipes in the upper stage is adjacent to each other. A first notch is provided between the pipe groups of the above and is cut out from the upper edge of the fin plate toward the upstream side in the flow direction of the combustion gas, and is between the pair of adjacent pipe groups in the lower stage. A second notch portion notched from the lower edge of the fin plate toward the downstream side in the flow direction of the combustion gas is provided, and the first notch portion is included in the pair of pipes having the tip of the notch on the upper stage. The notch depth reaches the hot water supply pipe, and a first burring is provided on the distal end side peripheral edge of the first notch, and the first burring extending toward the downstream side in the combustion gas flow direction. The position of the end of one burring was set to the position of the joint between the hot water supply pipe and the circulation pipe in the pair of upper pipe groups at the maximum.

Further, in claim 2 , the hot water supply pipes are arranged side by side in the upstream side and the circulation pipes are arranged in the downstream direction in the vertical direction with respect to the flow direction of the combustion gas to form a pair of pipe groups, and the pair of pipe groups are formed in two upper and lower stages. In a heat exchanger in which a plurality of fin plates are penetrated as a grid-like arrangement to heat the water flowing through each pipe, the upper edge of the fin plates is between the pair of adjacent pipe groups in the upper stage. A first notch is provided from the pipe toward the upstream side in the flow direction of the combustion gas, and is located between the pair of adjacent pipe groups in the lower stage and downstream from the lower edge of the fin plate in the flow direction of the combustion gas. A second notch is provided, and the first notch has a notch depth at which the tip of the notch reaches the hot water supply pipe of the pair of pipes in the upper stage. A first burring is provided on the peripheral edge of the one notch on the tip end side, and the second notch has a notch depth at which the tip of the notch reaches the hot water supply pipe of the pair of pipes in the upper stage. The tip end side of the second cutout portion has an open annular hole formed in a substantially diamond shape, and is the peripheral edge of the substantially diamond-shaped open annular hole, which is a straight portion of four sides forming the substantially diamond shape. Of these, it is assumed that the second burring is provided on the straight portions on the two sides located on the downstream side in the flow direction of the combustion gas.

Further, in claim 3 , each of the straight portions of the two sides constituting the second burring is arranged so as to face the hot water supply pipe in the upper stage located in a direction substantially orthogonal to the straight portion. ..

According to claim 1 of the present invention, the first notch has a notch depth at which the tip of the notch reaches the hot water supply pipe of the pair of upper pipe groups, and is located on the distal peripheral edge of the first notch. Because the first burring is provided, the heat transfer area near the upper hot water supply pipe increases, the amount of heat absorbed by the upper hot water supply pipe located near the first burring increases, and the upper hot water supply pipe increases. Since it functions to circulate the combustion gas traveling from the front flow side to the side from the side of the upper hot water supply pipe to the wake (rear) side, heat is absorbed even on the wake side of the upper hot water supply pipe. The amount of heat absorbed by the upper hot water supply pipe is increased, and the heat exchange efficiency can be improved.

Further, according to claim 2, in the first burring, the position of the end of the first burring extending toward the downstream side in the combustion gas flow direction is the position of the hot water supply pipe and the circulation pipe in the pair of upper pipe groups at the maximum. By setting it to the position of the joint, the combustion gas is induced to the wake side of the upper hot water supply pipe to increase the amount of heat absorption, and the upper circulation pipe does not become overheated when the hot water supply is used alone. It is possible to prevent the boiling of the water inside.

Further, according to claim 3, the second notch has a notch depth at which the tip of the notch reaches the hot water supply pipe of the pair of upper pipe groups, and the tip side of the second notch has a substantially diamond shape. It has an open ring hole formed in a shape, and is the peripheral edge of a substantially diamond-shaped open ring hole. Of the four straight sides forming a substantially diamond shape, two sides located on the downstream side in the flow direction of combustion gas. Since the second burring is provided in the straight portion of the above, the heat transfer area in the vicinity of the upper hot water supply pipe is increased, the amount of heat absorption in the upper hot water supply pipe located in the vicinity of the second burring is increased, and the heat absorption amount is increased. Since it functions to guide the combustion gas that has passed through the pair of lower pipes from the front flow side to the side of the upper hot water supply pipe, the amount of heat absorbed by the upper hot water supply pipe increases and the heat exchange efficiency is improved. It is something that can be done.

Further, according to claim 4, each of the straight portions of the two sides constituting the second burring is arranged so as to face the upper hot water supply pipe located in a direction substantially orthogonal to the straight portion. The heat absorbed by the two burring is transferred from the straight parts on the two sides to the upper hot water supply pipes facing each other via the fin plate, so that the upper hot water supply pipes absorb heat evenly and uniformly. It is possible to improve the heat exchange efficiency.

The schematic block diagram of the one-can two-water channel type combustion apparatus provided with the heat exchanger of one Embodiment of this invention. FIG. 1 is a cross-sectional view taken along the line AA of FIG. The perspective view of the fin plate constituting the heat exchanger. The figure which shows the flow of the combustion gas in the heat exchanger of one Embodiment of this invention. FIG. 5 is an enlarged view of a main part in the vicinity of a pair of pipe groups in the upper stage in the heat exchanger according to the embodiment of the present invention.

An embodiment of the heat exchanger according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a one-can two-water channel type combustion device provided with a heat exchanger according to an embodiment of the present invention, and details will be described below.

1 is a one-can, two-water channel type combustion device capable of generating hot water used by a hot water tap or the like provided at a predetermined location and heating hot water supplied to a heat dissipation terminal (here, tub 2), and 3 is kerosene. A vaporizer made of aluminum die cast that vaporizes the fuel oil, 4 is a vaporizer heater that is provided in the vaporizer 3 and heats the fuel oil to a temperature at which it can be vaporized. In a mixing chamber made of aluminum die cast in which vaporized vaporized gas and primary air are premixed, the vaporizer 3 and the mixing chamber 5 form a vaporizing unit 6 for vaporizing fuel oil.

Reference numeral 7 denotes a combustion unit which is provided on the back side of the vaporizer 3 in the upper part of the mixing chamber 5 and burns the premixed gas premixed in the mixing chamber 5. The combustion unit 7 and the vaporizer 6 form a burner. Is. Further, 8 is formed integrally with the vaporizer 3, and is a plurality of endothermic fins protruding above the combustion unit 7 on the back surface of the vaporizer 3, and at the time of combustion, the combustion heat is fed back to the vaporizer 3 as the heat of vaporization. The amount of electricity supplied to the vaporizer heater 4 is suppressed as much as possible.

9 is a nozzle that sprays fuel oil onto the vaporizer 3, 10 is an electromagnetic pump that pumps fuel oil to the nozzle 9 via an oil supply pipe 11, 12 is a combustion fan, and the combustion fan 12 is a vaporizer 3 via an air passage 13. Combustion air that communicates with the inlet and the air chamber 15 between the combustion unit 7 and the cover frame 14 and is sucked from the suction port 16 is supplied to the vaporizer 3 as primary air for premixing, and is supplied to the air chamber 15. Is supplied as secondary air that passes through the side of the vaporizer 3 and is burned in the combustion unit 7 from below the mixing chamber 5.

Reference numeral 17 denotes a combustion can body having a combustion chamber 18 formed therein and a heat exchanger 19 provided. The heat exchanger 19 is a heat (combustion flame and combustion) generated by combustion of a burner (combustion unit 7) in the combustion chamber 18. A fin tube type can that heats the water flowing through the hot water supply pipe 21 and the bath pipe 22 by absorbing the heat from the gas) into the hot water supply pipe 21 and the bath pipe 22 as a circulation pipe via a plurality of fin plates 20. It consists of a two-water channel type heat exchanger, and the hot water supply pipe 21 is communicated and connected via a hot water supply U-shaped pipe 23 to form a meandering hot water supply heat exchange flow path, and the bath pipe 22 is connected via a bath U-shaped pipe 24. The combustion gas that has passed through the heat exchanger 19 is exhausted to the outside of the machine through the exhaust port 25. The detailed configuration of the heat exchanger 19 will be described later.

Reference numeral 26 denotes a water supply pipe that circulates water supplied from the water supply source to the inlet of the hot water supply heat exchange channel in the heat exchanger 19, and 27 is connected to the outlet of the hot water supply heat exchange channel in the heat exchanger 19. A hot water supply pipe that supplies hot water heated by the heat exchanger 19 to a hot water tap (not shown) provided at a predetermined location, 28 is a water supply bypass pipe branched from the water supply pipe 26, and 29 is a hot water supply pipe 27 and a water supply bypass pipe. It is a mixing valve provided at a connection portion with 28 and capable of mixing hot water from the hot water supply pipe 27 and water from the water supply bypass pipe 28 and changing the mixing ratio thereof. The hot water supply pipe 21, the U-shaped pipe 23 for hot water supply, the water supply pipe 26, the hot water supply pipe 27, and the water supply bypass pipe 28 constitute a hot water supply circuit through which water flows.

Reference numeral 30 is a bath return pipe for circulating bath water from the bath 2 to the inlet of the bath heat exchange channel in the heat exchanger 19, and 31 is connected to the outlet of the bath heat exchange channel in the heat exchanger 19. The bath going pipe that supplies the bath water heated by the heat exchanger 19 to the bath 2 and 32 are circulation pumps that are provided in the bath return pipe 30 and circulate the bath water. The bath pipe 22, the U-shaped pipe 24 for the bath, the bath return pipe 30, and the bath going pipe 31 constitute a bath circuit as a circulation circuit for circulating bathtub water.

Here, the operation of the one-can two-water channel type combustion device 1 will be described. The one-can two-water channel type combustion device 1 burns the burner (combustion unit 7) when a hot water supply request is generated, and the hot water supply pipe of the heat exchanger 19 is generated. By heating the water for hot water supply flowing through 21, the burner (combustion unit 7) is burned by using the hot water supply alone to supply the hot water tap provided at a predetermined location and by generating a request for reheating the bath water. The reheating single use that heats the bath water flowing through the bath pipe 22 of the heat exchanger 19 and supplies the heated bath water to the bath 2 by the drive of the circulation pump 32, and the hot water supply request and the reheating request occur at the same time. In some cases, hot water supply and reheating can be performed at the same time. Since a common burner (combustion unit 7) is used to heat the heat exchanger 19, the bath water staying in the bath pipe 22 is also heated when the hot water supply is used alone, and the reheating alone is used. Occasionally, the water for hot water supply that stays in the hot water supply pipe 21 is also heated.

Next, the detailed configuration of the heat exchanger 19 will be described with reference to FIGS. 2 to 3.
FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, which is a front view of a main part of the heat exchanger 19, and FIG. 3 is a perspective view of a fin plate 20 constituting the heat exchanger 19.

The heat exchanger 19 includes a plurality of hot water supply pipes 21 (10 hot water supply pipes 21 in this embodiment) through which water for hot water supply as a fluid to be heated flows, and a plurality of pipes through which bath water as a fluid to be heated flows. It is composed of a bath pipe 22 (10 bath pipes 22 in this embodiment) and a plurality of fin plates 20 arranged at predetermined intervals along the axial direction of the hot water supply pipe 21 and the bath pipe 22. A pair of hot water supply pipes 21 are arranged side by side in the vertical direction with the hot water supply pipe 21 on the upstream side and the bath pipe 22 on the downstream side (with the hot water supply pipe 21 on the bottom and the bath pipe 22 on the top) with respect to the flow direction of the combustion gas. A common burner (combustion) is formed by arranging a pair of pipe groups 33 in a grid pattern in two upper and lower stages (in this embodiment, 10 pairs of pipe groups 33 are arranged) and penetrating a plurality of fin plates 20. Part 7) is used to heat each of the hot water supply water flowing through the hot water supply pipe 21 and the bath water flowing through the bath pipe 22.

Each fin plate 20 includes a plurality of Dharma-shaped insertion holes 34 for passing a pair of pipe groups 33 (a hot water supply pipe side burring 34a and a bath pipe side burring 34b of the insertion holes 34 raised from the surface of the fin plate 20). ) Is formed, and the brazing material holes for inserting the brazing material into the two locations above the portion of the insertion hole 34 through which the bath pipe 22 is inserted and the upper two locations on the outer periphery of the hot water supply pipe side burring 34a. 35 is formed, and the hot water supply pipe 21 and the bath pipe 22 are brazed to the inner edges of the burrings 34a and 34b of the insertion holes 34 by the brazing material inserted into the brazing material hole 35, and the hot water supply pipe 21 and the bath are formed. The joint portion between the pipe 22 and the pipe 22 is also joined by brazing and fixed to the fin plate 20.

Further, each fin plate 20 is formed with a plurality of through holes 36 which are outside the insertion holes 34 and along the bath pipe 22, and the through holes 36 reduce the amount of heat absorbed by the bath pipe 22. It has an effect of preventing the bathtub water in the bath pipe 22 from boiling when the hot water supply is used alone.

Further, each fin plate 20 has a first notched portion 37 (in this embodiment, one fin) formed of a first gap notched in the vertical direction from the upper edge of the fin plate 20 toward the upstream side in the combustion gas flow direction. Four first notches 37) are formed per plate 20, and the surface of the fin plate 20 is formed on the distal edge of the first notch 37 located on the upstream side in the combustion gas flow direction of the first notches 37. The first burring 38 is provided, and when the fin plate 20 is viewed from the front (viewed from the axial direction of the hot water supply pipe 21 and the bath pipe 22), the first burring 38 is located on the distal edge of the first notch 37. It has a substantially U shape so as to follow the shape. It is assumed that the first notch 37 is formed from the upper edge of the fin plate 20 toward the upstream side in the combustion gas flow direction, but the upper edge here is in the vertical direction of the drawing (FIG. 2). The upper edge of the fin plate 20 essentially means the edge side of the fin plate 20 located on the most downstream side in the flow direction of the combustion gas.

Further, each fin plate 20 is a pair of upper pipes slightly above the substantially central portion of a rectangular space surrounded by four pairs of pipe groups 33 arranged in a rectangular shape in the upper and lower stages of the plurality of pairs of pipe groups 33. A second notch formed by an open annular hole 39 formed in a substantially diamond shape at a position closer to the group 33 and a second gap 40 notched continuously from the open annular hole 39 to the lower edge of the fin plate 20. 41 (in this embodiment, four second notches 41 per fin plate 20) is formed. It is assumed that the second gap 40 (second notch 41) is formed up to the lower edge of the fin plate 20, but the lower edge here is lower in accordance with the vertical direction of the drawing (FIG. 2). Up to the point of expressing it as an edge, the lower edge of the fin plate 20 essentially means the edge side of the fin plate 20 located on the most upstream side in the flow direction of the combustion gas.

Further, of the four straight side straight portions forming the substantially rhombus shape, which are the peripheral edges of the substantially rhombus-shaped open annular hole 39, the two straight portions located on the downstream side in the flow direction of the combustion gas and their straight portions. A second burring 42 raised from the surface of the fin plate 20 is provided on the curved portion connecting the spaces, and the second burring 42 is provided in the front view of the fin plate 20 (viewed from the axial direction of the hot water supply pipe 21 and the bath pipe 22). The burring 42 has a substantially inverted V shape so as to follow the shape of the peripheral edge on the tip end side of the second notch 41.

Further, side edge bent pieces 43 that are bent in the right angle direction and brazed to the inner wall of the combustion can body 17 are provided on the left and right side edges of each of the fin plates 20.

Next, the flow of the combustion gas passing through the heat exchanger 19 will be described with reference to FIG. 4, but here, the flow of the combustion gas other than the combustion gas entering the open annular hole 39 will be described. The flow of the combustion gas is shown by a broken line.
The combustion gas generated by the combustion in the burner (combustion unit 7) flows into the heat exchanger 19 and enters the open annular hole 39 and the combustion gas other than the combustion gas entering the open annular hole 39. As shown by the broken line, the combustion gas other than the combustion gas that enters the opening ring hole 39 first rises from the front flow side to the side of the lower hot water supply pipe 21. Subsequently, it passes from the side side to the rear side of the lower bath pipe 22, and from the front flow side of the upper hot water supply pipe 21, the straight portion of the upper hot water supply pipe 21 and the second burring 42 facing the hot water supply pipe 21. It passes between the outer wall, passes between the upper hot water supply pipe 21 side side and the first burring 38 outer wall, passes the upper bath pipe 22 side side, and flows out from the heat exchanger 19. It is something to go.

Here, the structure around the pair of upper pipe groups 33 located on the downstream side in the combustion gas flow direction in the heat exchanger 19 and the flow of the combustion gas will be described in detail with reference to FIG.
First, the first cutout portion 37 is between a pair of adjacent pipe groups 33 in the upper stage (left and right intermediate positions), and is cut out in the vertical direction from the upper edge of the fin plate 20 toward the upstream side in the combustion gas flow direction. The tip of the notch is formed to have a notch depth that reaches substantially the center position of the hot water supply pipe 21 among the pair of pipe groups 33 on the upper stage side in the front view, and the first notch 37. A first burring 38 is provided in a substantially U-shape along the peripheral edge on the tip side so as to go from the tip of the first notch 37 toward the downstream side in the combustion gas flow direction from the substantially central position of the hot water supply pipe 21. By providing the first burring 38, the heat transfer area in the vicinity of the upper hot water supply pipe 21 increases, the amount of heat absorbed in the upper hot water supply pipe 21 located in the vicinity of the first burring 38 increases, and the figure. As shown by the broken line of 5, the provision of the first burring 38 allows the combustion gas traveling from the front flow side to the side of the upper hot water supply pipe 21 to be lateral to the upper hot water supply pipe 21. Since it functions to circulate from the side to the wake (back) side, heat is also absorbed on the wake side of the upper hot water supply pipe 21, and the amount of heat absorbed by the upper hot water supply pipe 21 increases, improving the heat exchange efficiency. Can be done.

Further, among the first burring 38, the position of the end 38a of the first burring 38 extending toward the downstream side in the combustion gas flow direction along the distal edge side peripheral edge of the first notch 37 is a pair of upper pipe groups at the maximum. The position L on the same line as the joint between the hot water supply pipe 21 and the bath pipe 22 in 33 is set. This is because when the position of the end 38a of the first burring 38 exceeds the position L on the same line as the joint portion, the first burring 38 is provided up to the position of the upper bath pipe 22 and is on the upper side when the hot water supply is used alone. The bath water in the bath pipe 22 absorbs the heat of the combustion gas flowing along the side of the bath pipe 22 on the upper stage side and the heat transfer from the first burring 38, resulting in an overheated state and boiling. This is because the position of the end 38a of the first burring 38 is set to a position L on the same line as the joint portion between the hot water supply pipe 21 and the bath pipe 22 in the pair of upper pipe groups 33 at the maximum. While inducing combustion gas to the wake side of the upper hot water supply pipe 21 to increase the amount of heat absorption, the upper bath pipe 22 does not become overheated when the hot water supply is used alone, and the bath water in the bath pipe 22 is boiled. It can be prevented.

Next, the second notch 41 is between a pair of adjacent pipe groups 33 in the lower stage (left and right intermediate positions), and is cut vertically from the lower edge of the fin plate 20 toward the downstream side in the combustion gas flow direction. It is formed so as to be notched, and the tip of the notch (the position on the most downstream side in the combustion gas flow direction in the open annular hole 39) is the position of the upper hot water supply pipe 21 (combustion gas in the upper hot water supply pipe 21) in the front view. It is the notch depth that reaches the position above the most upstream position in the flow direction), and is the peripheral edge of the substantially diamond-shaped open annular hole 39 located on the tip side of the second notch 41, forming a substantially diamond shape. By providing the second burring 42 in the straight portion of the two sides located on the downstream side in the flow direction of the combustion gas among the straight portions of the four sides, the heat transfer area in the vicinity of the hot water supply pipe 21 in the upper stage is increased, and the heat transfer area is increased. 2 The amount of heat absorbed by the upper hot water supply pipe 21 located near the burring 42 increases, and as shown by the broken line in FIG. 5, the second burring 42 is provided, so that a pair of lower pipes are provided. Since it functions to guide the combustion gas that has passed through the group 33 from the front flow side to the side of the upper hot water supply pipe 21, heat is absorbed by the front flow side and the side of the upper hot water supply pipe 21 and is used in the upper stage. The amount of heat absorbed by the hot water supply pipe 21 is increased, and the heat exchange efficiency can be improved.

Further, since each of the straight portions on the two sides constituting the second burring 42 is arranged so as to face the upper hot water supply pipe 21 located in a direction substantially orthogonal to the straight portion, the inside of the open annular hole 39. The heat absorbed by the second burring 42 from the combustion gas (not shown) that has entered the water is transferred from the straight portions on the two sides to the upper hot water supply pipes 21 facing each other via the fin plate 20. Therefore, it is possible to uniformly absorb heat to each of the upper hot water supply pipes 21 without bias, and it is possible to improve the heat exchange efficiency.

It should be noted that, of the four straight side straight portions forming the substantially rhombus shape, which is the peripheral edge of the substantially rhombus-shaped open annular hole 39, burring is provided on the two straight portions located on the upstream side in the flow direction of the combustion gas. However, this is to reduce the heat transfer area by not providing the burring so that the lower bath pipe 22 does not absorb excessive heat, and the inside of the lower bath pipe 22 when the hot water supply is used alone is used. It prevents the boiling of bath water.

Further, as shown in FIG. 5 and the like, the first notch 37 is formed so as to face the second notch 41, but the notches do not interfere with each other and the fins are in between. The plate 20 is interposed, and in the front view of the fin plate 20 (viewed from the axial direction of the hot water supply pipe 21 and the bath pipe 22), both the first notch 37 and the second notch 41 are interposed. It has an overlap allowance with the upper hot water supply pipe 21, and the first cutout portion 37 has a larger overlap allowance with the upper hot water supply pipe 21 than the second notch portion 41.

As described above, in the above configuration, the heat exchanger 19 transmits the amount of heat absorbed from the combustion gas to the hot water supply pipe 21 and the bath pipe 22 via the fin plate 20, and the hot water supply flows through the hot water supply pipe 21. It can be used for heating the water for heating and heating the bath water flowing in the bath pipe 22, and in particular, the first burring 38 and the second notch 41 provided on the tip side of the first notch 37. By the action of the second burring 42 provided on the tip side, the amount of heat absorbed by the upper hot water supply pipe 21 can be increased, and the heat exchange efficiency can be improved.

The present invention is not limited to the one embodiment described above. In the present embodiment, the heat exchanger 19 is a fin tube type that heats the water flowing through the hot water supply pipe 21 and the bath pipe 22. Although it is a can two-water channel type heat exchanger, instead of the bathtub 2, the heat dissipation terminal is a heat dissipation terminal 2 such as a floor heating panel that heats the air-conditioned space, and the circulation pipe is a heating pipe instead of the bath pipe 22. The heat exchanger 19 may be a fin tube type one-can two-water channel type heat exchanger that heats the hot water supply pipe 21 and the water flowing through the heating pipe, and the one-can two-water channel type combustion device 1 may be used. As for the fuel of the above, gas fuel such as city gas or propane gas may be used instead of fuel oil such as kerosene.

Further, in the present embodiment, the flow of the combustion gas passing through the heat exchanger 19 is such that the lower edge side of the fin plate 20 is the upstream side and the upper edge side of the fin plate 20 is the downstream side. , The so-called back combustion, in which the burner is provided above the heat exchanger 19 and the flow of combustion gas passing through the heat exchanger 19 flows from top to bottom. In the case of the equation, the heat exchanger 19 shown in FIG. 2 may be arranged upside down, and the edge side of the fin plate 20 having the first notch 37 becomes the downstream side in the flow direction of the combustion gas. The effect of the heat exchanger 19 of the present invention described above can be exhibited as long as the relationship that the edge side of the fin plate 20 having the notch 41 is on the upstream side in the flow direction of the combustion gas is not broken. It is a thing.

19 Heat exchanger 20 Fin plate 21 Hot water supply pipe 22 Bath pipe 33 Pair of pipes 37 First notch 38 First burring 38a Termination of first burring 39 Open ring hole 41 Second notch 42 Second burring

Claims (3)

A pair of pipe groups are formed by arranging hot water supply pipes on the upstream side and circulation pipes on the downstream side in the vertical direction with respect to the flow direction of the combustion gas. In a heat exchanger that penetrates the fin plate and heats the water flowing through each pipe, it is between the pair of adjacent pipe groups in the upper stage and upstream from the upper edge of the fin plate in the flow direction of combustion gas. A first notch is provided so as to be cut out toward the side, and a first notch is provided between the pair of adjacent pipe groups in the lower stage and is notched from the lower edge of the fin plate toward the downstream side in the flow direction of the combustion gas. Two notches are provided, and the first notch has a notch depth at which the tip of the notch reaches the hot water supply pipe of the pair of pipes in the upper stage, and the peripheral edge on the tip side of the first notch. Is provided with a first burring, and the terminal position of the first burring extending toward the downstream side in the combustion gas flow direction of the first burring is the same as that of the hot water supply pipe in the pair of upper pipe groups at the maximum. A heat exchanger characterized in that the position of the joint with the circulation pipe is reached.
A pair of pipe groups are formed by arranging hot water supply pipes on the upstream side and circulation pipes on the downstream side in the vertical direction with respect to the flow direction of the combustion gas. In a heat exchanger that penetrates the fin plate and heats the water flowing through each pipe, it is between the pair of adjacent pipe groups in the upper stage and upstream from the upper edge of the fin plate in the flow direction of combustion gas. A first notch notched toward the side is provided, and a first notch is provided between the pair of adjacent pipe groups in the lower stage and is notched from the lower edge of the fin plate toward the downstream side in the flow direction of the combustion gas. Two notches are provided, and the first notch has a notch depth at which the tip of the notch reaches the hot water supply pipe of the pair of pipes in the upper stage, and the peripheral edge on the tip side of the first notch. Is provided with a first burring, and the second notch has a notch depth at which the tip of the notch reaches the hot water supply pipe of the pair of pipes in the upper stage. The tip side has an open annular hole formed in a substantially diamond shape, which is the peripheral edge of the substantially diamond-shaped open annular hole, and is the flow direction of combustion gas among the straight portions of the four sides forming the substantially diamond shape. the linear portion of the two sides located on the downstream side, the heat exchanger shall be the wherein the second burring is provided.
Wherein each of the second two sides of the straight portion constituting the burring, according to claim 2, characterized in that arranged so as to face the hot water supply pipe of the upper positioned in a direction substantially orthogonal to the straight line portion Heat exchanger.

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