JP2012122663A - Heat exchanger and water heater using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger and a water heater using the heat exchanger having a high degree of freedom in setting positions to provide an inflow port and an outflow port of a heated liquid.SOLUTION: A heat exchange unit 64 is formed by joining the outer peripheral edges of two plate-like members 66 to each other, and the heat exchange units 64 are stacked to constitute the heat exchanger. Communicating parts 68 serving for communication between heated liquid passages 220 of the heat exchange units 64 are formed at two parts between the adjacent heat exchange units 64. A transverse part 76 formed by the contact or approach of recesses 74 provided at the two plate-like members 66 interrupts a flow of bath water that flows into the heated liquid passage 220 from one of the communicating parts 68 and is going to short-circuit to the other of the communicating parts 68. The heated liquid passage 220 is thereby formed in annular shape. The passage width L of the heated liquid passage 220 on both sides of a transverse direction of the transverse part 76 with the transverse part 76 held in between is equal to the passage width L of heated liquid passage 220 on both sides of a direction orthogonal to the transverse direction with the transverse part 76 held in between.

Description

  The present invention relates to a stacked heat exchanger and a water heater using the same.

As a conventional heat exchanger, as disclosed in Patent Document 1, a heat exchanger is formed by stacking a plurality of tubes formed by joining two tube plates.
In the heat exchanger of Patent Document 1, two communication portions that communicate the flow paths of adjacent tubes are provided between the tubes formed in a U shape or a straight line, and one end side in the stacking direction. In the tube, hot water supply hot water outlets and hot water outlets are provided on the same stacking direction as the two communicating portions.

  Hot water flowing into the heat exchanger from the hot water supply port passes through the communication portion in the same stacking direction as the hot water supply port between the tubes, and flows out from the hot water outlet through the communication portion in the same stacking direction as the hot water outlet. . In each tube, hot water supplied from one of the two communication portions is directed toward the other communication portion.

JP 2004-125189 A

  However, as in the heat exchanger of Patent Document 1, in a U-shaped or linear tube whose both ends are closed, two communicating portions are connected to both ends of the tube so that there is no dead space in the flow path formed by the tube. It is necessary to form the hot water supply port and the hot water outlet of the heat exchanger on both ends of the tube in accordance with the communication portion.

  Thus, in the configuration of the heat exchanger that provides the inlet into which the liquid to be heated flows in and the outlet from which the liquid to be heated flows out at both ends of the tube, the positions where the inlet and the outlet are provided are fixed. In accordance with the space where the heat exchanger is installed and the parts installed around the heat exchanger, the positions where the inlet and the outlet are provided in the heat exchanger cannot be freely set.

As a result, the position where the pipe is connected to the inlet and the outlet of the heat exchanger is fixed, which causes a problem that the degree of freedom of the piping when connecting the pipe to the heat exchanger is low.
The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a heat exchanger having a high degree of freedom in positions where the inlet and outlet of the liquid to be heated are provided, and a water heater using the heat exchanger. And

  In the invention according to any one of claims 1 to 7, the heat exchange units are formed by joining the outer peripheral edge portions of the two plate-like members, and each heat exchange unit has a flat liquid flow path to be heated. A heat exchange unit group which is stacked in the thickness direction of the heat exchange unit, and forms a gas flow path through which the combustion gas generated by the burner passes between adjacent heat exchange units, and a gas flow path. And a communication portion that is provided at two locations across and communicates between the liquid flow paths to be heated of adjacent heat exchange units. In the heat exchange unit on one end side in the stacking direction, the communication portion is provided in the stacking direction. An inflow port and an outflow port for the liquid to be heated are provided on the plate-like member opposite to the side on which the heat is supplied, and the heat exchange unit is connected to the communication portion provided at two locations in the liquid flow path to be heated. Of the communication part provided in two places. And a heated liquid flow path has a cross section which forms the annular by interfering with the flow of the heated liquid to be short-circuited.

  According to this configuration, the liquid to be heated that has flowed into the liquid flow path to be heated from one of the communication portions provided at two places is obstructed by the crossing portion in a flow that attempts to short-circuit between the communication portions. The heating liquid flow path is divided into both sides in the transverse direction of the transverse part and flows in an annular shape, and merges at the other communicating part.

  Therefore, even if the position where the communication portion is provided on the circumference of the annular heated liquid channel, that is, the position where the inlet and outlet of the heated liquid are changed, dead space does not occur in the heated liquid channel. The heated liquid flows through the annular heated liquid flow path. Thereby, since the freedom degree of the position which provides the inflow port and outflow port of a to-be-heated liquid in a heat exchanger becomes high, the freedom degree of the handling of piping connected to a heat exchanger becomes high.

In the invention according to claim 2, the transverse portion is formed at the center of the heated liquid channel.
As a result, the flow rate of the liquid to be heated that flows into the heated liquid flow path from one communicating portion, is divided into the heated liquid flow paths on both sides in the transverse direction of the transverse portion, and merges at the other communicating portion is It becomes almost equal in the heated liquid flow path on both sides in the direction. As a result, the to-be-heated liquid which flows through the to-be-heated liquid flow path of the transverse direction both sides of a crossing part is heated equally in a heat exchange unit.

According to the third aspect of the present invention, the communication portions provided at two places are arranged at point-symmetrical positions with the crossing portion as the center.
According to this configuration, even if the heat exchange unit is rotated by 180 °, the positions of the communication portions provided at the two positions do not change. Therefore, even if the heat exchange unit is rotated halfway, the positions of the communication portions are matched to perform heat exchange. Units can be stacked. Thereby, since a heat exchange unit can be laminated | stacked without considering the rotation position of a heat exchange unit, a heat exchanger can be manufactured easily.

  In the invention according to claim 4, the communicating portion provided at each of the two locations, and the inlet and the outlet provided on the same stacking direction as the communicating portions at each location are the heated liquid channel. Is in contact with the inner peripheral edge of the inner wall surface of the heat exchange unit.

  According to this configuration, when the heat exchanger is mounted so that one of the inlet or the outlet is on the lower side and the other is on the upper side, one of the inlet or the outlet located on the lower side and the inlet or the outlet are arranged. The lower end positions of the communicating portion provided on the same stacking direction as the one and the heated liquid flow path coincide with each other.

  As a result, when an operation for extracting the liquid to be heated from the device to which the heat exchanger is attached, for example, in the case of a water heater, a well-known water draining operation is performed, the liquid to be heated in the liquid channel to be heated It does not accumulate in the flow path but flows out of the heat exchanger from one of the inlet or outlet located on the lower side. As a result, the liquid to be heated can be prevented from freezing in the heat exchanger. Furthermore, since the foreign material and dirt contained in the liquid to be heated flow out of the heat exchanger together with the liquid to be heated, it is possible to prevent the foreign material and dirt from accumulating in the heat exchanger.

  In the invention according to claim 5, the inner wall surface of the heat exchange unit that is in contact with the communication portion and the inlet provided in one of the two locations, and the communication portion and the outlet provided in the other of the two locations, respectively. Has a concave portion formed by inclining the inner wall surfaces on both sides of a portion in contact with a tangent passing through a portion where the communication portion and the inner peripheral edge of the inner wall surface are in contact with each other by a predetermined angle.

  According to this configuration, when the heat exchanger is mounted so that one of the inlet or the outlet is on the lower side and the other is on the upper side, the mounting position in the rotation direction of the heat exchanger is centered on the stacking direction of the heat exchange units. Even if there is a slight deviation, when the operation of extracting the liquid to be heated from the device to which the heat exchanger is attached is performed, the liquid to be heated gathers toward the communication portion located on the lower side and one of the inflow port or the outflow port. As a result, even if the mounting position of the heat exchanger in the rotational direction is slightly deviated, the liquid to be heated in the liquid flow path to be heated passes through the communicating portion and is located outside the heat exchanger from one of the inlet or outlet located below. Flows out.

  In the invention according to claim 6, the width of the heated liquid channel formed on both sides in the transverse direction by the transverse part across the transverse part and on both sides in the direction orthogonal to the transverse direction across the transverse part is equal.

  According to this configuration, the channel cross-sectional area of the heated liquid channel formed in an annular shape centering on the transverse portion is substantially equal on the circumference. As a result, the flow rates of the liquid to be heated flowing in the liquid flow path to be heated are equal on the circumference and are equal in the cross section of the flow path. As a result, the liquid to be heated flowing through the liquid flow path to be heated can be heated evenly.

  In the invention according to claim 7, a primary heat exchanger provided separately from the hot water supply side heating circuit, the main burner for heating the water passing through the hot water supply side heating circuit, and the hot water supply side heating circuit as the main heating circuit, And a secondary heating circuit having a secondary heat exchanger that recovers the latent heat of the combustion gas that has passed through the primary heat exchanger, and a secondary burner that heats water through the secondary heating circuit. The heat exchanger according to any one of claims 1 to 6 is used as a heat exchanger.

  According to this structure, since the freedom degree of the position which provides the inflow port and the outflow port of the water which is a to-be-heated liquid in a heat exchanger is high, it is used as a secondary heat exchanger of a subheating circuit. When the heat exchanger according to any one of the above is attached to the water heater, the sub-heating circuit of the sub-heating circuit depends on the installation space of the secondary heat exchanger of the sub-heating circuit in the water heater and the components installed around it. The positions of the inlet and outlet provided in the secondary heat exchanger can be appropriately set. As a result, the degree of freedom of the piping connected to the secondary heat exchanger of the sub-heating circuit is increased.

The schematic diagram which shows the water heater by 1st Embodiment. The perspective view which shows the state which assembled | attached the secondary heat exchanger of the hot water supply side and the bath side. (A) shows the perspective view of the secondary heat exchanger by the side of a bath, and (B) is the exploded perspective view. (A) is a front view of the secondary heat exchanger on the bath side, (B) is a cross-sectional view taken along line BB in (A), and (C) is a cross-sectional view taken along line CC in (A). (A) is a view in the direction of arrow A in (B), and (B) is a schematic cross-sectional view of one heat exchange unit taken out in (C) of FIG. 4. FIG. 5 is a schematic cross-sectional view in which a part of FIG. 4B is taken out in order to explain a gas flow path between adjacent heat exchange units. (A) is a schematic diagram explaining the equalization effect | action of the gas flow by a protrusion, (B) is a schematic diagram explaining the removal effect | action of the air film by a protrusion. The schematic diagram which shows the to-be-heated liquid flow path of the secondary heat exchanger by the side of the bath by 2nd Embodiment. The schematic diagram which shows the to-be-heated liquid flow path of the secondary heat exchanger by the side of the bath by 3rd Embodiment.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
The schematic diagram of the water heater by 1st Embodiment of this invention is shown in FIG.

(Structure of the water heater 10)
The water heater 10 includes a fan motor 12, a fan 14 that is rotationally driven by the fan motor 12, a hot water supply unit 20 that supplies hot water to hot water outlets such as a hot water tap and a bathtub, and the warming and reheating of hot water in the bathtub. A heat retaining unit 50 is provided, and a controller (not shown) that controls the operation of the hot water supply unit 20 and the heat retaining unit 50 is provided. Moreover, the piping of the hot water supply unit 20 and the piping of the heat retaining unit 50 are communicated with each other through a communication pipe (not shown) so that hot water can be supplied into the bathtub through the hot water supplying unit 20 and the heat retaining unit 50.

  In the water heater 10, the hot water supply unit 20 includes a burner 22, 24 accommodated in the combustion chamber 200, a sensible heat recovery primary heat exchanger 26, and a latent heat recovery secondary heat exchanger 30. Are arranged sequentially from top to bottom.

  In the water heater 10, the heat retaining unit 50 includes a burner 52 housed in the combustion chamber 202, a sensible heat recovery primary heat exchanger 54, and a latent heat recovery secondary heat exchanger 60. Are arranged sequentially from top to bottom.

  The hot water supply unit 20 and the heat retaining unit 50 are in communication with each other, and the fan 14 is rotationally driven by the fan motor 12, whereby the combustion chamber 200 on the hot water supply unit 20 side, the combustion chamber 202 on the heat retaining unit 50 side, and Air can be supplied to each of these.

  Solenoid valves are installed in the branch pipes of the gas supply pipes that supply gas to the burners 22 and 24 and the burner 52, respectively, and in the main pipe of the gas supply pipe that supplies gas to the branch pipes. By opening and closing these solenoid valves, gas supply to the burners 22 and 24 and the burner 52 is controlled.

  As shown in FIG. 2, the secondary heat exchanger 30 of the hot water supply unit 20 and the secondary heat exchanger 60 of the heat retaining unit 50 are attached to a common frame body 40. The frame body 40 includes a combustion gas inlet 210 through which the combustion gas of the burners 22 and 24 that has passed through the primary heat exchanger 26 is introduced into the secondary heat exchanger 30, and a burner 52 that has passed through the primary heat exchanger 54. The combustion gas inlet 212 for introducing the combustion gas into the secondary heat exchanger 60 is formed.

  The combustion gases introduced from the combustion gas inlets 210 and 212 respectively pass through the secondary heat exchangers 30 and 60 and are discharged from the exhaust port 214. When the combustion gas passes through the secondary heat exchangers 30 and 60, it heats the water by exchanging heat with the internal water.

  The secondary heat exchanger 30 of the hot water supply unit 20 recovers the latent heat of the combustion gas of the burners 22 and 24 that has passed through the primary heat exchanger 26, and the secondary heat exchanger 60 of the heat retaining unit 50 performs primary heat exchange. It is installed to recover the latent heat of the combustion gas of the burner 52 that has passed through the vessel 54.

  In the hot water supply unit 20, hot water supplied from the water supply is first supplied to the secondary heat exchanger 30, and hot water heated by the secondary heat exchanger 30 is supplied to the primary heat exchanger 26. Heated. The hot water heated in the hot water supply unit 20 is discharged from a hot water tap or the like of the kitchen, and also through the above-described communication pipe that connects the piping of the hot water supply unit 20 and the piping of the heat retaining unit 50 and the piping of the heat retaining unit 50. Hot water is poured into the bathtub. In addition, the communication pipe which supplies the hot water heated from the hot water supply part 20 to the bathtub is provided with an electromagnetic valve which is opened when the hot water is discharged to the bathtub.

  Also in the heat retaining unit 50, the bath water pumped up from the bath tub by a pump or the like is first supplied to the secondary heat exchanger 60, and the bath water heated by the secondary heat exchanger 60 is the primary heat exchanger 54. To be further heated. The bath water heated by the primary heat exchanger 54 is returned to the bathtub.

  A control unit (not shown) incorporates a microcomputer including a CPU, a ROM, a RAM, and the like, and controls operations of the burner igniter and the various electromagnetic valves, motors, pumps, and the like described above.

(Secondary heat exchanger 60 of the heat retaining unit 50)
Next, the secondary heat exchanger 60 of the heat retaining unit 50 will be described.
As shown in FIG. 3, the secondary heat exchanger 60 is mainly composed of a heat exchange unit group 62 in which flat heat exchange units 64 are stacked. Each heat exchange unit 64 is formed by joining the outer peripheral edge portions of two plate-like members 66 formed by press working by brazing.

  In FIG. 3B, reference numeral 222 indicates a flow of bath water flowing in the stacking direction between adjacent heat exchange units 64, and reference numeral 224 indicates a flow of bath water flowing in the heat exchange unit 64.

  As shown to (A) of FIG. 4, the external shape of the heat exchange unit 64 is a rectangle. Since the secondary heat exchanger 60 is attached to the frame body 40 with the long side of the heat exchange unit 64 in the horizontal direction and the short side in the vertical direction, the height of the water heater 10 can be made as low as possible. .

  As shown in FIGS. 4B and 4C, a flat heated liquid flow path 220 through which bath water flows is formed inside the heat exchange unit 64, and between adjacent heat exchange units 64. Is formed with a gas passage 230 through which the combustion gas of the burner 52 passes.

In FIGS. 3 and 4, some symbols are omitted in order to avoid complexity of the drawings.
In the heat exchange unit 64, two plate-like members 66 are formed with two communicating portions 68 that communicate with the heated liquid passage 220 of the adjacent heat exchange unit 64 across the gas passage 230. ing. In the heat exchange unit 64A on one end side in the stacking direction, one of the communicating portions formed on the plate member 66 on the opposite side to the plate member 66 facing the adjacent heat exchange unit 64 is the flow of bath water. It functions as an inlet 70, and the other of the communicating portions functions as an outlet 72 for bath water. A connection joint 80 connected to the pipe is brazed to the inflow port 70 and the outflow port 72 via a reinforcing plate 82.

  In the heat exchange unit 64B on the other end side in the stacking direction with respect to the heat exchange unit 64A on the one end side in the stacking direction in which the inlet 70 and the outlet 72 are provided, a plate shape facing the adjacent heat exchange unit 64 The plate-like member 66 opposite to the member 66 is not formed with a communication portion 68 or the formed communication portion 68 is sealed with a stopper.

  A concave portion 74 that is recessed in the stacking direction toward the inside of the heat exchange unit 64 is formed at the center of the two plate-like members 66 that form the heat exchange unit 64. When the two concave portions 74 are brought into contact with or approach each other in a state where the two plate-like members 66 are joined, the transverse portion 76 is formed. The crossing part 76 is provided across the communication parts 68 provided at two places in the heated liquid channel 220.

As shown in FIG. 5A, the communication portions 68 provided at two locations of the plate-like member 66 are arranged at point-symmetrical positions around the center position 76 a of the transverse portion 76.
FIG. 5A is a view of FIG. 5B as viewed from the A direction. One of the two plate-like members 66 constituting the heat exchange unit 64 is removed, and the inside of the heat exchange unit 64 is shown. It is the figure shown typically. FIG. 5B is a schematic cross-sectional view of the heat exchange unit 64 in which one heat exchange unit 64 in FIG. 4C is taken out.

  As described above, since the communication portions 68 provided at two places are arranged at point-symmetrical positions around the center position 76a of the crossing portion 76, even if the heat exchange unit 64 is rotated by 180 °, two places are provided. The position of the communication portion 68 provided in the position does not change. As a result, since the heat exchange unit 64 can be laminated without considering the rotational position of the heat exchange unit 64, the secondary heat exchanger 60 can be easily manufactured by laminating the heat exchange unit 64.

  As shown in FIGS. 3 and 4, a plurality of protrusions 78 are provided around the recess 74 on the surface of the two plate-like members 66 forming the heat exchange unit 64. The protrusion 78 may be formed on the plate-like member 66 by press working, or may be joined to each plate-like member 66 by welding or the like. The protrusions 78 facing each other of the adjacent heat exchange units 64 support the adjacent heat exchange units 64 when the heat exchange units 64 are laminated and brazed, so that when the heat exchange units 64 are laminated, the heat exchange units 64 64 prevents tilting. Thereby, when manufacturing the secondary heat exchanger 60, the heat exchange unit 64 can be laminated easily.

(Heating liquid flow path 220)
As shown in FIG. 5, in the heat exchange unit 64, the bath water that has flowed into the heated liquid flow path 220 from one of the communicating portions 68 provided at two locations has a flow that tends to be short-circuited to the other of the communicating portions 68. It is obstructed by the crossing 76. As a result, the bath water flowing in from one of the communicating portions 68 flows separately on both sides of the transverse portion 76 in the transverse direction of the liquid to be heated 220 and merges at the other communicating portion 68. As a result, an annular heated liquid flow path 220 is formed in the heat exchange unit 64 with the cross section 76 as the center.

  The channel width L of the heated liquid channel 220 on both sides of the transverse part 76 across the transverse part 76 and the heated liquid channel 220 on both sides in the direction perpendicular to the transverse direction across the transverse part 76. The channel width L is equal. That is, the channel cross-sectional areas of the annular heated liquid channel 220 are substantially equal.

  As a result, the flow rate of the bath water flowing through the heated liquid channel 220 becomes equal on both sides in the transverse direction of the transverse portion 76 and on both sides in the orthogonal direction perpendicular to the transverse direction, and the flow rate of the bath water is increased in the heated liquid channel 220. It becomes equal on the circumference and the channel cross section. As a result, the bath water flowing through the heated liquid channel 220 is evenly heated by the combustion gas passing through the gas channel 230 formed between the adjacent heat exchange units 64.

In addition, since the channel cross-sectional area of the annular heated liquid passage 220 is substantially equal, the pressure loss in the heated liquid passage 220 can be reduced, and the amount of bath water flowing can be ensured.
(Widened portion 232)
FIG. 6 is a schematic cross-sectional view in which a part of FIG. 4B is taken out in order to explain the gas flow path 230 formed between the adjacent heat exchange units 64. In the gas flow path 230 between the adjacent heat exchange units 64, a widened portion 232 is formed in the center of the gas flow path 230 along the gas flow direction by the recess 74 formed in the plate member 66. Yes. In the widened portion 232, the flow path width of the gas flow channel 230 is wider in the stacking direction than the periphery of the widened portion 232, and thus the flow path resistance is smaller than that of the widened portion 232.

  Here, when the widened portion 232 is not provided and the width of the gas flow path 230 in the stacking direction is uniform, the combustion gas flowing in from one side of the gas flow path 230 (left side in FIG. 4A) is In addition, the secondary heat exchanger 60 having a small flow path resistance is used instead of flowing through the gas flow path 230 between the upper and lower portions of FIG. 4A and flowing out from the other side (the right side in FIG. 4A). Therefore, it tends to flow outside the center of the gas flow path 230 (upper and lower sides in FIG. 4A).

  On the other hand, in this embodiment, since the widened portion 232 is formed at the center of the gas flow path 230, the combustion gas that has flowed into the gas flow path 230 is not only outside the secondary heat exchanger 60, It is also attracted to the widened portion 232 having a small flow resistance provided at the center of the gas flow channel 230. Further, since the widened portion 232 is formed along the gas flow direction, the gas flow toward the widened portion 232 is directed toward the center of the gas flow path 230 by the length of the widened portion 232 along the gas flow direction. Attracted. Thereby, the combustion gas flows through the gas flow path 230 evenly.

(Operation of the protrusion 78)
As described above, the protrusion 78 not only supports the adjacent heat exchange unit 64 when the heat exchange units 64 are stacked, but also includes a central portion of the gas flow path 230 as shown in FIG. This obstructs the flow of the combustion gas going outward, and forms a flow toward the center. As a result, the combustion gas that tends to flow outside the central portion of the gas flow path 230 tends to move toward the central portion side, so that the combustion gas flows evenly through the gas flow path 230.

  Further, when bath water flows through the heated liquid flow path 220, the air on the surface of the heat exchange unit 64 is cooled, so that an air film having a lower temperature than the combustion gas as shown in FIG. 240 is formed on the surface of the heat exchange unit 64. If the surface of the heat exchange unit 64 is covered with the air film 240, the combustion gas cannot directly contact the heat exchange unit 64, and the air film 240 becomes a heat insulation film. descend.

  Therefore, in the present embodiment, since the protrusion 78 is provided on the surface of the plate-like member 66, the combustion gas collides with the protrusion 78, and the air film 240 is removed. Thereby, since combustion gas contacts the heat exchange unit 64 directly, the heating efficiency of the bath water by combustion gas improves.

  According to 1st Embodiment demonstrated above, the bath water which flowed in into the cyclic | annular to-be-heated liquid flow path 220 from one of the communication parts 68 provided in two places has the flow which tries to short-circuit between the communication parts 68. Since it is obstructed by the crossing part 76, the heated liquid flow path 220 flows separately on both sides in the transverse direction of the crossing part 76, and merges at the other communication part 68.

  Therefore, even if the position where the communication portion 68 is provided on the circumference of the annular heated liquid flow path 220, that is, the position where the bath water inlet 70 and the outlet 72 are provided is changed, a dead space is formed in the heated liquid flow path 220. The bath water flows through the annular heated liquid passage 220 without the occurrence of water. Thereby, since the freedom degree of the position which provides the inflow port 70 and the outflow port 72 of bath water in a heat exchanger is high, the freedom degree of the management of piping connected to a heat exchanger becomes high.

  In the first embodiment, the primary heat exchanger 26 and the secondary heat exchanger 30 of the hot water supply unit 20 form the hot water supply side heating circuit of the present invention, and the primary heat exchanger 54 and the secondary heat exchange of the heat retaining unit 50. The vessel 60 forms the subheating circuit of the present invention.

In the first embodiment, the burners 22 and 24 correspond to the main burner of the present invention, and the burner 52 corresponds to the auxiliary burner of the present invention.
In the first embodiment, the secondary heat exchanger 60 corresponds to the heat exchanger of the present invention, the heat exchange unit group 62 corresponds to the heat exchange unit group of the present invention, and the heat exchange unit 64 of the present invention. The plate-like member 66 corresponds to the plate-like member of the present invention, the communication portion 68 corresponds to the communication portion of the present invention, the inlet 70 corresponds to the inlet of the present invention, and the outlet 72 corresponds to the outlet of the present invention, the cross section 76 corresponds to the cross section of the present invention, the heated liquid flow path 220 corresponds to the heated liquid flow path of the present invention, and the gas flow path 230 corresponds to the present invention. This corresponds to the gas flow path.

[Second Embodiment]
A heat exchanger according to a second embodiment of the present invention is shown in FIG. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals. FIG. 8 is a diagram schematically showing the inside of the heat exchange unit 90 by removing one of the two plate-like members 92 constituting the heat exchange unit 90, as in FIG.

  In the secondary heat exchanger 60 of the first embodiment, in the heat exchange unit 64 formed in a quadrangular shape, the communicating portion 68 is connected to the central portion along the long side on both sides in the direction orthogonal to the transverse direction across the transverse portion 76. Was provided.

  On the other hand, in the heat exchange unit 90 of the second embodiment, in the heat exchange unit 90 formed in a square shape, the communication portion 68 is provided diagonally across the transverse portion 96 formed by the two concave portions 94. ing.

  Also in this case, it is desirable that the crossing portion 96 is formed at the center portion of the heated liquid flow path 220, and the communication portions 68 provided at two places are crossing portions around the center position 96 a of the crossing portion 96. It is desirable that they are arranged at point-symmetrical positions with respect to 96.

  Then, the bath water flowing in from one of the communication portions 68 flows separately on both sides in the transverse direction of the transverse portion 96 through the heated liquid flow path 220, and merges at the other communication portion 68. As a result, an annular liquid passage 220 to be heated is formed inside the heat exchange unit 90 with the transverse portion 96 as the center.

In the second embodiment, the heat exchange unit 90 corresponds to the heat exchange unit of the present invention, the plate-like member 92 corresponds to the plate-like member of the present invention, and the transverse portion 96 corresponds to the transverse portion of the present invention.
[Third Embodiment]
A heat exchanger according to a third embodiment of the present invention is shown in FIG. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals. FIG. 9 is a diagram schematically showing the inside of the heat exchange unit 100 by removing one of the two plate-like members 102 constituting the heat exchange unit 100, as in FIG. 5A and FIG. is there.

  The crossing part 76 is formed at the center of the heated liquid flow path 220, and the communication parts 68 provided at two places are point-symmetric with respect to the crossing part 76 around the center position 76 a of the crossing part 76. Placed in position.

Also in the heat exchange unit 100, an annular heated liquid channel 220 is formed around the crossing 76.
The communication portions 68 provided at two locations are in contact with the inner peripheral edge 106 of the inner wall surface 104 of the heat exchange unit 100 that forms the heated liquid flow path 220. Therefore, the inlet 70 and the outlet 72 of the heat exchanger formed in the same stacking direction as the communication portions 68 formed at the two locations are also connected to the inner peripheral edge 106 of the inner wall surface 104 of the heat exchange unit 100. It touches.

  The inflow port 70 and the communication portion 68 in the same stacking direction as the inflow port 70 and the outflow port 72 and the communication portion 68 in the same stacking direction as the outflow port 72 are in contact with the inner peripheral edge 106 of the inner wall surface 104. The inner wall surface 104 of the location 300 has a recess 108 formed by inclining the inner wall surfaces 104 on both sides with a predetermined angle θ with respect to the tangent line 302 passing through the contact location 300. Yes.

  Thus, when the heat exchanger is attached so that the inlet 70 or the outlet 72 is on the lower side in the vertical direction, the heat exchanger may be attached with a slight rotation about the stacking direction of the heat exchange unit 100 as an axis. When the water draining operation is performed, bath water gathers toward the inflow port 70 or the outflow port 72 positioned on the lower side in the vertical direction and the communication portion 68, that is, toward the bottom of the recess 108. As a result, even if the assembly position in the rotational direction of the heat exchanger is slightly shifted, the bath water in the heated liquid flow path 220 passes through the communication portion 68 and is heated from the inlet 70 or the outlet 72 located on the lower side in the vertical direction. It flows out of the exchanger.

  Therefore, it is possible to prevent the bath water from remaining in the heat exchange unit 100 and freezing in the winter. Further, foreign substances and dirt in the bath water can be prevented from accumulating in the heat exchange unit 100.

  In the third embodiment, the heat exchange unit 100 corresponds to the heat exchange unit of the present invention, the plate member 102 corresponds to the plate member of the present invention, the inner wall surface 104 corresponds to the inner wall surface of the present invention, The peripheral edge 106 corresponds to the inner peripheral edge of the present invention, the concave portion 108 corresponds to the concave portion of the inner wall surface of the present invention, the contacting portion 300 corresponds to the contacting portion of the present invention, and the tangent 302 is the tangent of the present invention. It corresponds to.

[Other Embodiments]
In the above-described embodiment, the communication part is installed point-symmetrically with the crossing part as the center. On the other hand, the liquid to be heated that has flowed in from one of the two communication portions provided at two locations is prevented from flowing short-circuited to the other communication portion, and the transverse portion prevents the liquid to be heated to have an annular shape around the transverse portion. If it is formed, the communication part provided in two places does not need to be installed in the point symmetrical position centering on the crossing part. Further, the crossing portion may be provided at a position shifted from the central portion of the heated liquid channel.

  Moreover, in the said embodiment, the heat exchanger of this invention was attached so that the inflow port of a to-be-heated liquid might become an upper direction and an outflow port might become a downward direction. On the other hand, you may attach the heat exchanger of this invention so that an outflow port may become upper and an inflow port may become downward.

  Moreover, in the said embodiment, the heat | fever of this invention manufactured by laminating | stacking the heat exchange unit which joins the outer periphery part of two plate-shaped members, and has a flat cyclic | annular to-be-heated liquid flow path inside. The exchanger was used as a secondary heat exchanger for recovering the latent heat of the burner fuel gas in the heat retaining section for the bathtub of the water heater. On the other hand, you may apply the heat exchanger of this invention to the secondary heat exchanger of the heat retention part for floor heating, for example besides the heat retention part for bathtubs. And if the heat exchanger of this invention heats the to-be-heated liquid which flows not only in water but the inside, you may apply to what kind of use.

  Further, in the third embodiment, the inlet 70 and the communication portion 68 in the same stacking direction as the inlet 70, and the portions in contact with the outlet 72 and the communication portion 68 in the same stacking direction as the outlet 72, respectively. The inner wall surface may be formed in a straight line instead of a concave shape.

  As described above, the present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

10: Hot water heater, 20: Hot water supply section, 22, 24: Burner (main burner), 26: Primary heat exchanger (hot water supply side heating circuit, main heating circuit), 30: Secondary heat exchanger (hot water supply side heating circuit) , Main heating circuit), 50: heat retaining section, 52: burner (sub-burner), 54: primary heat exchanger (sub-heating circuit), 60: secondary heat exchanger (sub-heating circuit), 62: heat exchange unit Group, 64, 90, 100: heat exchange unit, 66, 92, 102: plate-like member, 68: communication portion, 70: inflow port, 72: outflow port, 74, 94: recess, 76, 96: crossing portion, 78: Projection, 104: Inner wall surface, 106: Inner peripheral edge, 108: Recess, 220: Heated liquid flow path, 300: Touched part, 302: Tangent, θ: Predetermined angle

Claims (7)

Each heat exchange unit is formed by joining the outer peripheral edge portions of two plate-like members, each heat exchange unit has a flat heated liquid passage inside, and is laminated in the thickness direction of the heat exchange unit A heat exchange unit group forming a gas flow path through which combustion gas generated by a burner passes between the adjacent heat exchange units;
A communication portion provided at two locations across the gas flow path, and communicating the heated liquid flow paths of the adjacent heat exchange units;
With
In the heat exchange unit on one end side in the stacking direction, an inlet and an outlet for the liquid to be heated are provided on the plate-like member on the side opposite to the side on which the communication portion is provided in the stacking direction. And
The heat exchange unit is provided across the communication portions provided at two locations in the heated liquid flow path, and is to be heated to short-circuit between the communication portions provided at two locations. It has a cross section that forms the heated liquid passage in an annular shape by obstructing the flow of the liquid,
A heat exchanger characterized by that.   The heat exchanger according to claim 1, wherein the crossing portion is formed at a central portion of the heated liquid channel.   3. The heat exchanger according to claim 2, wherein the communication portions provided at two locations are arranged at point-symmetric positions with respect to the transverse portion.   The communication portion provided at each of the two locations, and the inlet and the outlet provided on the same stacking direction as the communication portion at each location form the heated liquid flow path. The heat exchanger according to any one of claims 1 to 3, wherein the heat exchanger unit is in contact with an inner peripheral edge of an inner wall surface of the heat exchange unit.   The communication portion and the inlet provided at one of the two locations, and the inner wall surface of the location where the inner peripheral edge is in contact with the communication portion and the outlet provided at the other of the two locations, 5. The heat exchanger according to claim 4, wherein a concave portion is formed by inclining the inner wall surfaces on both sides of the contacting portion with a predetermined angle with respect to a tangent line passing through the contacting portion. .   The widths of the heated liquid passages formed on both sides in the transverse direction by the transverse part across the transverse part and on both sides in the direction perpendicular to the transverse direction across the transverse part are equal. The heat exchanger according to any one of claims 1 to 5. A hot water supply side heating circuit;
A main burner for heating the water flow of the hot water supply side heating circuit;
A sub heating circuit provided separately from the hot water supply side heating circuit, which is a main heating circuit, and having a primary heat exchanger and a secondary heat exchanger that recovers the latent heat of the combustion gas that has passed through the primary heat exchanger; ,
A sub-burner for heating the water passing through the sub-heating circuit;
With
The heat exchanger according to any one of claims 1 to 6 is used as the secondary heat exchanger of the sub-heating circuit.
A water heater characterized by that.

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