JP6715032B2 - Bath water heater - Google Patents

Description

The present invention relates to a bath water heater including a hot water heating unit and a bath heating unit.

Conventionally, a bath water heater having a function of heating hot water in a bath has been widely put into practical use. In this bath water heater, a burner and a heat exchanger are provided in a combustion chamber formed in the appliance, and the combustion chamber is partitioned into a hot water heating unit and a bath heating unit, and a water pipe is connected to the heat exchanger of the hot water heating unit. It has been known that a hot water supply pipe and a hot water supply pipe are connected to each other and a return pipe and a forward pipe of the bathtub are connected to a heat exchanger of a bath heating unit.
In addition, the heat exchanger has a primary heat exchanger (main heat exchanger) that mainly recovers sensible heat and a secondary heat exchanger (sub heat exchanger) that mainly recovers latent heat in order to improve thermal efficiency. It may be formed by. In the bath water heater, for example, as disclosed in Patent Document 1, the casing of the secondary heat exchanger is partitioned into a hot water supply side region and a bath side region, and a hot water supply side secondary heat exchanger provided in the hot water supply side region is provided. The heat transfer pipe is connected to the water supply pipe and the hot water supply side primary heat exchanger, while the heat transfer pipe of the bath side secondary heat exchanger provided in the bath side area is connected to the return pipe and the bath side primary heat exchanger. .. Combustion exhaust gas from the burner enters each region from the back surface of the casing, flows through the gaps of the heat transfer tubes, and is discharged from the exhaust port on the front surface of the casing.

JP, 2013-72569, A

In the bath water heater that uses the bath-side secondary heat exchanger, the combustion exhaust gas that has passed through the bath-side secondary heat exchanger is smoothly discharged from the exhaust port while the bath-side burner is burning due to the air pressure supplied by the air supply fan. .. However, when the burner on the bath side burns and the supply air pressure from the air supply fan disappears, the drainage generated by heat exchange in the secondary heat exchanger on the bath side becomes vapor containing nitric acid and accumulates in the casing. Then, it is discharged from the exhaust port over time. For this reason, the generated steam is likely to come into contact with the surface of the device to cause dew condensation, which may corrode the surface of the device.

Therefore, the present invention has an object to provide a bath water heater capable of suitably suppressing corrosion of the appliance surface due to drain vapor even if the bath water secondary heat exchanger is provided. is there.

In order to achieve the above object, the invention according to claim 1 is a hot water supply heating unit having a hot water supply side burner, a hot water supply side primary heat exchanger, and a hot water supply side secondary heat exchanger,
A bath-side burner, a bath-side primary heat exchanger, and a bath-heating unit having a bath-side secondary heat exchanger,
The hot-water supply side secondary heat exchanger and the bath-side secondary heat exchanger were housed in a casing, and the hot-water supply side primary heat exchanger and the bath-side primary heat exchanger passed through either the front or rear wall of the casing. An inlet for the combustion gas to flow in and an exhaust outlet for discharging the inflowing combustion gas are provided on the other wall, and a hot water supply side exhaust passage that passes through the hot water supply side secondary heat exchanger is provided in the casing. And a bath-side exhaust passage that passes through the bath-side secondary heat exchanger and is formed into a partition,
In the casing, while forming a cooling flow path, the combustion gas passing through the bath-side exhaust passage is brought into contact with the inner surface of the wall where the exhaust port is formed and then guided to the exhaust port ,
A horizontal guide plate is provided on the inner surface of the wall where the exhaust port is formed so as to project from the upper side of the exhaust port to the inflow side and partition the inner space of the exhaust port into upper and lower parts .

According to the invention described in claim 1, since the cooling gas passage is formed in the casing so that the combustion gas comes into contact with the inner surface of the wall on the exhaust port side, the combustion gas accumulated after the combustion of the bath side burner is cooled. By passing through the flow path, the ambient temperature of the combustion gas is lowered, and the generation of drain inside the casing is promoted. Therefore, when exhausted to the outside of the equipment, it is possible to suppress the occurrence of dew condensation on the equipment surface, and even if the equipment is equipped with a secondary heat exchanger on the bath side, the corrosion of the equipment surface due to drain vapor is preferably suppressed. can do.
Further , the cooling flow path can be easily formed by the guide plate.

It is sectional drawing of a bath water heater. It is a perspective view of a secondary heat exchanger. It is a longitudinal cross-sectional view of the bath side secondary heat exchanger part in the secondary heat exchanger. It is a longitudinal cross-sectional view of the hot water supply side secondary heat exchanger part in the secondary heat exchanger. (A) is a perspective view from the front of the casing in which a side wall and a heat transfer tube of the bath side secondary heat exchanger are omitted, and (B) is a perspective view in which an upper plate is further omitted. (A) is a perspective view from the rear of the casing in which the side wall and the heat transfer tube of the bath side secondary heat exchanger are omitted, and (B) is a perspective view in which the upper plate is further omitted.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing an example of a bath water heater. The bath water heater 1 is provided with a combustion device 2 in a housing (not shown), and the combustion device 2 is arranged in a can body 3 communicating with the inside thereof from below, a burner unit 4, a primary heat exchanger 5, and a secondary heat exchanger. The heat exchanger 6 is formed in this order.
First, in the burner unit 4, the first burner group 7 and the second burner group 8 are arranged side by side in the left-right direction. Each of the burner groups 7 and 8 is formed by arranging a plurality of flat burners 9 having a flame hole on the upper end surface side by side in the left-right direction, and supplies gas to the rear end of the mixing pipe 10 provided at the bottom of each burner 9. The primary air for combustion is supplied together with the gas by facing a nozzle (not shown) connected to the pipe. Here, the first burner group 7 is the hot water supply side burner and the second burner group 8 is the bath side burner. The number of burners 9 of the first burner group 7 having a large capacity is set to be larger than that of the second burner group 8. There is.

Next, in the primary heat exchanger 5, the hot water supply side primary heat exchanger 11 located above the first burner group 7 and the bath side primary heat exchanger 12 located above the second burner group 8 are arranged in the left-right direction. Will be installed side by side. Each of the heat exchangers 11 and 12 is composed of a plurality of fins 13, 13... Stacked at predetermined intervals in the front-rear direction, and a heat transfer tube 14 penetrating each fin 13 in a meandering manner.
Further, in the secondary heat exchanger 6, there is a hot water supply side secondary heat exchanger 15 which is located above the hot water supply side primary heat exchanger 11 and is composed of a plurality of spirally wound heat transfer tubes 16.16. A bath-side secondary heat exchanger 17, which is located above the bath-side primary heat exchanger 12 and is composed of a plurality of spirally wound heat transfer tubes 18, 18,. As shown in FIG. 2, the secondary heat exchangers 15 and 17 have a box-like shape including a front wall 20, a rear wall 21, an upper wall 22, a lower wall 23, and left and right side walls 24 and 24. It is housed in the casing 19.

As shown in FIGS. 3 and 4, an inlet 25 for the combustion gas passing through the primary heat exchanger 5 is formed in the rear wall 21 of the casing 19, and an exhaust port 26 is formed in the front wall 20 in the left-right direction. ing. The front wall 20, the rear wall 21, the upper wall 22, and the lower wall 23 of the casing 19 are the upper portion of the exhaust port 26 of the front wall 20 and the upper portion of the upper wall 22 of the rear wall 21 of the inflow port 25. By assembling the integrated upper plate 19A, the lower plate 19B in which the lower portion of the front wall 20 including the exhaust port 26 and the lower wall 23 and the lower portion of the rear wall 21 including the inflow port 25 are integrated. It is formed.
Further, inside the casing 19, a partition plate 27 for partitioning the hot water supply side secondary heat exchanger 15 and the bath side secondary heat exchanger 17 is provided in the front-rear direction, and the inside of the casing 19 has an inlet 25. The combustion gas flowing in from the hot water supply side secondary heat exchanger 15 passes through the heat transfer pipes 16, 16... Between the hot water supply side exhaust passages 28 and the combustion gas flowing in from the inflow port 25 is discharged into the bath. A bath-side exhaust passage 29 is formed which passes between the heat transfer tubes 18, 18 of the side secondary heat exchanger 17 and is discharged from the exhaust port 26.

Further, an inlet 30 and an outlet 31 of the heat transfer pipe 16 of the hot water supply side secondary heat exchanger 15 are provided on the right side wall 24 of the casing 19, a water supply pipe 32 is connected to the inlet 30, and an outlet 31 is provided at the outlet 31. A connection pipe 33 is connected to the inlet of the heat transfer pipe 14 of the hot water supply side primary heat exchanger 11. A hot water outlet pipe 34 is connected to the outlet of the heat transfer pipe 14 of the hot water supply side primary heat exchanger 11.
On the other hand, the left side wall 24 of the casing 19 is provided with an inlet 35 and an outlet 36 of the heat transfer tube 18 of the bath side secondary heat exchanger 17, and a return pipe 37 from the bathtub is connected to the inlet 35 and an outlet. A connection pipe (not shown) to the inlet of the heat transfer pipe 14 of the bath side primary heat exchanger 12 is connected to 36. An outlet pipe 38 to the bathtub is connected to the outlet of the heat transfer pipe 14 of the bath-side primary heat exchanger 12.

Further, in the casing 19, below the upper wall 22, a ceiling plate 39 that is inclined downward toward the front is provided. In front of this ceiling plate 39, a hanging portion 41 that hangs from a rear position spaced apart from the front wall 20 in parallel with the front wall 20 and extends to a position slightly lower than the vertical center in the casing 19, A rectifying plate 40 is provided which includes a left and right guide portion 42 as a guide plate that extends obliquely upward and forward from the lower end of the hanging portion 41 and is connected to the upper end of the exhaust port 26. The partition plate 27 is formed to a position where it abuts on the hanging portion 41 of the flow straightening plate 40. Therefore, when the combustion gas passing from the inflow port 25 through the hot water supply side exhaust passage 28 and the bath side exhaust passage 29 comes into contact with the drooping part 41 of the flow straightening plate 40, the combustion gas descends along the drooping part 41 as indicated by the dotted arrow. After that, it goes around the lower part of the hanging part 41, moves forward along the guide part 42, and is discharged from the exhaust port 26.

However, in the bath-side exhaust passage 29 in the casing 19, a quadrangular opening 43 is formed in the hanging portion 41 of the rectifying plate 40 as shown in FIGS. It communicates with the inside of 40. Therefore, the inner space of the exhaust port 26 is partitioned into upper and lower parts by the guide portion 42 of the flow straightening plate 40 protruding rearward from the upper side of the exhaust port 26. Due to the opening 43 and the guide portion 42, most of the combustion gas passing through the bath-side exhaust passage 29 flows into the casing 19 from the opening 43 to the inside of the straightening vane 40, as shown by a dashed line in FIG. After coming into contact with the inner surface of the wall 20, the cooling flow path 44 is again formed from the opening 43 to the rear of the hanging portion 41, passes under the guide portion 42, and is discharged from the exhaust port 26.
Further, an inclined plate 45 is provided at the lower edge of the exhaust port 26 in the front wall 20 so as to project obliquely forward and upward, and the front end abuts the inner surface of the housing.

On the other hand, in the can body 3, between the lower partitioning member 46 located between the first burner group 7 and the second burner group 8, the hot water supply side primary heat exchanger 11 and the bath side primary heat exchanger 12. The middle partition member 47 and the partition plate 27 in the casing 19 serve as a hot water supply heating unit in which the first burner group 7, the hot water supply side primary heat exchanger 11 and the hot water supply side secondary heat exchanger 15 are arranged. It is partitioned into a hot water supply side combustion chamber 48, a second side burner group 8, a bath side primary heat exchanger 12, and a bath side combustion chamber 49 as a bath heating section in which a bath side secondary heat exchanger 17 is arranged. .. Reference numeral 50 is a thermistor for detecting the temperature of the combustion gas and monitoring the blockage of the fins. An air supply fan (not shown) is connected to the lower portion of the can body 3 so that the air sent from the air supply fan can be supplied to the combustion chambers 48, 49.

In the bath water heater 1 configured as described above, when the hot water tap provided on the hot water outlet pipe 34 is opened to allow water to flow through the equipment, the water from the water feed pipe 32 becomes the hot water supply side secondary heat exchanger. After passing through the heat transfer tube 16 of No. 15, it passes through the heat transfer tube 14 of the hot water supply side primary heat exchanger 11. On the other hand, a controller (not shown) provided outside the appliance ignites the first burner group 7 and rotates the air supply fan to supply combustion air to the first burner group 7. The combustion gas of the first burner group 7 passes through the hot water supply side primary heat exchanger 11 and the hot water supply side secondary heat exchanger 15 in this order in the hot water supply side combustion chamber 48, so that the hot water supply side primary heat exchanger 11 mainly Sensible heat is recovered, latent heat is mainly recovered in the hot water supply side secondary heat exchanger 15, and hot water of a predetermined temperature is tapped from the tap pipe 34.

Then, when the additional cooking switch provided in the controller is turned on, the controller drives the pump provided in the circulation path to the bath to ignite the second burner group 8 and rotate the air supply fan. Combustion air is supplied to the second burner group 8. Hot water from the bathtub passes through the heat transfer tube 18 of the bath side secondary heat exchanger 17 and then through the heat transfer tube 14 of the bath side primary heat exchanger 12, and the combustion gas of the second burner group 8 is In the combustion chamber 49, the bath-side primary heat exchanger 12 and the bath-side secondary heat exchanger 17 pass in this order. Therefore, the sensible heat is mainly recovered in the bath-side primary heat exchanger 12, and the latent heat is mainly recovered in the bath-side secondary heat exchanger 17, and the hot water in the bathtub is circulated and reheated.

At this time, in the secondary heat exchanger 6, the combustion gas flowing from the inflow port 25 through the primary heat exchanger 5 passes through the hot water supply side exhaust passage 28 or the bath side exhaust passage 29, respectively, and goes from the ceiling plate 39 to the straightening plate. It goes around the lower side of 40 and is discharged to the outside of the device through the exhaust port 26. In the bath-side exhaust passage 29, the combustion gas is smoothly discharged without being branched to the cooling flow path 44 due to the supply pressure from the supply fan.
Then, when the reheating is completed and the combustion of the second burner group 8 is stopped, the supply gas pressure from the supply fan disappears, so that the combustion gas accumulated in the bath-side exhaust passage 29 is cooled as described above. Almost all branches into the passage 44, and once enters the inside of the straightening vane 40 through the opening 43, comes into contact with the inner surface of the front wall 20, and then goes around below the guide portion 42 and is discharged. Therefore, the ambient temperature of the combustion gas is lowered, and drainage is likely to occur in the casing 19. Therefore, when exhausted to the outside of the device, it is possible to suppress the occurrence of dew condensation on the surface of the device. The drain generated in the casing 19 is received by the recess 51 formed in the front of the lower wall 23 that slopes downward and is discharged from the drain discharge pipe 52 provided in the recess 51 to a neutralizer (not shown). ..

As described above, according to the bath water heater 1 of the above-described embodiment, the combustion gas passing through the bath-side exhaust passage 29 is brought into contact with the inner surface of the front wall 20 where the exhaust port 26 is formed, and then the exhaust port is provided in the casing 19. By forming the cooling flow path 44 leading to 26, the combustion gas staying after the combustion of the second burner group 8 passes through the cooling flow path 44, the ambient temperature of the combustion gas is lowered, and the inside of the casing 19 is cooled. The generation of drain is promoted. Therefore, when exhausted to the outside of the appliance, it is possible to suppress the occurrence of dew condensation on the appliance surface, and even if the bath-side secondary heat exchanger 17 is provided, corrosion of the appliance surface due to drain vapor is preferably performed Can be suppressed.

It should be noted that the shape, size, number, etc. of the openings provided in the hanging portion of the current plate may be appropriately changed as long as the combustion gas can pass through the hanging portion and come into contact with the front wall.
Further, in the above-described embodiment, the cooling passage is formed by providing an opening in the hanging portion of the straightening vane, but the straightening plate is omitted and only the guide plate extending from the upper side of the exhaust port to the inlet side is provided and the cooling passage is provided. May be formed. In this case, the cooling flow path can be easily formed by the guide plate.
Further, in order to increase the area in which the combustion gas comes into contact with the front wall, unevenness or ribs are provided on the inner surface of the front wall, and in order to increase the passage time of the cooling flow path, the upper wall and the guide portion (guide plate) are It is also conceivable that the cooling passages are formed in a meandering shape by vertically staggering the plates in the vertical direction.

1...Bath water heater, 2...Combustion device, 3...Can body, 4...Burner unit, 5...Primary heat exchanger, 6...Secondary heat exchanger, 7...First burner group, 8·· Second burner group, 11·· Hot water supply side primary heat exchanger, 12·· Bath side primary heat exchanger, 15·· Hot water supply side secondary heat exchanger, 17·· Bath side secondary heat exchanger, 19・・Casing, 20・・Front wall, 25・・Inflow port, 26・・Exhaust port, 27・・Partition plate, 28・・Hot water side exhaust passage, 29・・Bath side exhaust passage, 40・・Rectification plate , 41... Hanging part, 42... Guide part, 43... Opening, 44... Cooling channel, 48... Hot water supply side combustion chamber, 49... Bath side combustion chamber

Claims (1)

A hot water supply heating section having a hot water supply side burner, a hot water supply side primary heat exchanger, and a hot water supply side secondary heat exchanger;
A bath-side burner, a bath-side primary heat exchanger, and a bath-heating unit having a bath-side secondary heat exchanger,
The hot water supply side secondary heat exchanger and the bath side secondary heat exchanger are housed in a casing, and the hot water supply side primary heat exchanger and the bath side primary heat exchange are provided on one of the front and rear walls of the casing. An inlet through which the combustion gas that has passed through the furnace flows, and an exhaust port through which the inflowing combustion gas is discharged is provided on the other wall, and the hot water supply side secondary heat exchanger is provided in the casing. A bath water heater in which a hot water supply side exhaust passage that passes through and a bath side exhaust passage that passes through the bath side secondary heat exchanger are formed by partitioning,
In the casing, while forming a cooling flow path, the combustion gas passing through the bath-side exhaust passage is brought into contact with the inner surface of the wall where the exhaust port is formed and then guided to the exhaust port ,
An inner surface of the wall in which the exhaust port is formed is provided with a horizontal guide plate that protrudes from the upper side of the exhaust port toward the inflow port and vertically divides an inner space of the exhaust port. Bath water heater.

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