JP2007303701A - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent corrosion of a sub-heat exchanger by drain and to discharge most of drain to the external through a drainage without scattering the drain to the air in a water heater comprising a main heat exchanger and the sub-heat exchanger. <P>SOLUTION: This water heater comprises a control unit performing the control to hold an opening/closing cover 9 in an approximate closed state by a stopper mechanism 23 after the stop of an operation, and to distribute the air to a surface of the sub-heat exchanger 7 by operating a fan 12 for 5 minutes, thus the drain attached to a surface of a water pipe 7a of the sub-heat exchanger 7 is dropped and the surface of the water pipe 7a is dried by the air distributed from the fan 12, and the dropped drain is discharged to the drainage 43 through a drain receiver 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus including a main heat exchanger and a sub heat exchanger, and in particular, prevents corrosion of the sub heat exchanger by removing drain adhered to the surface of the sub heat exchanger after the operation of the hot water apparatus is stopped. And it is related with what was comprised so that most drain might be discharged | emitted outside, without being scattered in the air.

  Conventionally, a hot water heater incorporates a main heat exchanger that recovers sensible heat from the combustion gas of the burner and a sub heat exchanger that recovers latent heat in addition to sensible heat that could not be recovered by the main heat exchanger. Some have improved the heat exchange efficiency of the combustion gas. During operation of the water heater, strong acid drain is condensed on the surface of the auxiliary heat exchanger due to latent heat recovery in the auxiliary heat exchanger, so a drain receiver that receives the drain is installed on the lower side of the auxiliary heat exchanger. In general, the drain that has fallen from the surface of the vessel is received by a drain receiver, introduced into a neutralizer through a drainage channel, neutralized in the neutralizer, and then discharged to a sewer.

Further, as a configuration for discharging the drain generated by the latent heat recovery in the auxiliary heat exchanger to the outside, there is a configuration in which the drain is discharged into the air without going through the drainage channel.
Patent Document 1 discloses a water heater provided with a drain collector below the auxiliary heat exchanger, and provided with a drain receiver and a nozzle for ejecting air sent from a combustion air supply fan in the drain collector. As disclosed, drain that has fallen from the auxiliary heat exchanger by the air jetted from the nozzle during operation of the apparatus is forcibly discharged from the air exhaust port to the outside.

Patent Document 2 discloses a water heater in which a drain evaporator is provided on the lower side of the auxiliary heat exchanger, and hot air sent from a combustion air supply fan is blown toward the drain evaporator, during operation of the apparatus. The drain received by the drain evaporator is evaporated by the hot air sent from the combustion air supply fan.
JP 2005-61792 A JP 2005-61791 A

  By the way, during operation of the hot water supply apparatus, condensed drain is continuously generated and adheres to the surface of the auxiliary heat exchanger, so that the drain tends to fall as large droplets. Combustion gas is no longer supplied to the heat exchanger, so that no new drain is generated, and the drain adhering to the surface of the auxiliary heat exchanger becomes difficult to fall.

In this way, if it is left in a state where strongly acidic drain adheres to the surface of the auxiliary heat exchanger, it is necessary to take measures because corrosion progresses in the auxiliary heat exchanger and durability decreases. Document 1 and Patent Document 2 do not disclose a technique for removing drain adhering to the surface of the auxiliary heat exchanger after the hot water supply apparatus is stopped and drying the surface of the auxiliary heat exchanger.
Further, in Patent Document 1 and Patent Document 2, when the operation of the hot water supply device is stopped, the combustion air supply fan is also stopped, so that not only the discharge of the drain to the outside stops but also the auxiliary heat exchanger. Drain adhering to the surface remains.

  Moreover, in patent document 1, since drain is forcedly discharged outside from an air exhaust port by the air ejected from the nozzle, the drain is scattered in the air, which is not very desirable in consideration of the influence on the environment. . Also in Patent Document 2, since hot air is blown toward the drain that has fallen into the drain evaporator, the drain may be scattered in the air as in Patent Document 1.

  An object of the present invention is to provide a hot water supply apparatus having a main heat exchanger and a sub heat exchanger, to prevent the sub heat exchanger from being corroded by the drain, and to provide a drainage channel without scattering most of the drain into the air. To be discharged to the outside.

  The hot water supply apparatus according to claim 1 is recovered by a burner that burns fuel, a fan that supplies combustion air to the burner, a main heat exchanger that recovers sensible heat from the combustion gas of the burner, and a main heat exchanger. A secondary heat exchanger that recovers latent heat in addition to the sensible heat that could not be obtained, an exhaust passage that exhausts exhaust gas after heat recovery in the secondary heat exchanger, and a secondary heat exchanger that recovers latent heat in the secondary heat exchanger In a hot water supply apparatus having a drain receiver for receiving drain generated on the surface of the exchanger and a drainage channel for discharging the drain received by the drain receiver, the fan is operated for a predetermined time after the hot water supply is stopped to perform auxiliary heat exchange. Control means for controlling the air to be blown to the surface of the vessel, the drain attached to the surface of the auxiliary heat exchanger is dropped by blowing from the fan and the surface of the auxiliary heat exchanger is dried, and the drained drain is drained. Through It is characterized in that it has configured to discharge the drainage channel Te.

  In this hot water supply apparatus, after the operation of the hot water supply apparatus is stopped, control is performed so that the fan is operated for a predetermined time by the control means to blow air to the surface of the auxiliary heat exchanger. Drain adhering to the surface of the sub heat exchanger is dropped by blowing air from the fan and the surface of the sub heat exchanger is dried, so that the drain adhering to the surface of the sub heat exchanger is removed during the recovery of latent heat. Corrosion of the heat exchanger can be prevented. At this time, by discharging the fallen drain to the drainage channel via the drain receiver, the drainage can be discharged to the outside after neutralization is performed by the neutralizer provided on the downstream side of the drainage channel.

  According to a second aspect of the present invention, there is provided a hot water supply apparatus according to the first aspect of the present invention, further comprising an opening / closing lid that suppresses the outflow of exhaust gas to the exhaust passage.

  According to a third aspect of the present invention, there is provided the hot water supply apparatus according to the second aspect of the invention, wherein the opening / closing lid is a rotating lid that rotates about a rotation shaft, and is opened when the fan is blown and is almost closed when the fan is stopped. It is characterized by comprising a rotating lid.

  According to a fourth aspect of the present invention, there is provided the hot water supply apparatus according to the third aspect of the present invention, further comprising stopper means for holding the open / close lid substantially in a closed state when the fan is operated by the control means.

  According to a fifth aspect of the present invention, there is provided a hot water supply apparatus according to any one of the first to fourth aspects, further comprising a temperature sensor that detects an ambient temperature, wherein the control means is configured to detect the ambient temperature detected by the temperature sensor at a predetermined value or less. The fan is controlled so as not to operate.

  According to the first aspect of the present invention, the control means causes the fan to operate for a predetermined time after stopping the operation of the hot water supply device and blows air to the surface of the auxiliary heat exchanger to drop the drain adhering to the surface of the auxiliary heat exchanger and Since the surface of the heat exchanger is dried, drainage adhering to the surface of the auxiliary heat exchanger during latent heat recovery can be completely removed, and corrosion of the auxiliary heat exchanger can be prevented. In addition, since the drained drain is discharged to the drainage channel via the drain receiver, the drain can be discharged to the outside after being neutralized with a neutralizer, and the environment is not adversely affected.

  According to the second aspect of the present invention, since the opening / closing lid for suppressing the exhaust gas flow into the exhaust passage is provided, the opening / closing lid is substantially closed when the fan is operated for a predetermined time after the operation of the water heater is stopped. As a result, it is possible to prevent the drain from being blown off by the air blown from the fan and most of the drain to the exhaust passage, and the drain is not scattered into the air through the exhaust passage.

  According to the invention of claim 3, the opening / closing lid is a rotating lid that rotates about the rotation axis, and is configured to be in an open state when the fan is blown and close in a closed state when the fan is stopped. When the operation is stopped, the rotating lid is almost closed, and rainwater or the like can be prevented from entering the hot water supply apparatus through the exhaust passage.

  According to the invention of claim 4, when the fan is operated by the control means, the stopper means for holding the opening / closing lid substantially in the closed state is provided, so that the fan is operated for a predetermined time after the hot water supply device is stopped. In addition, most of the drain can be reliably prevented from flowing into the exhaust passage, and the drain does not scatter into the air through the exhaust passage.

  According to the invention of claim 5, the temperature sensor for detecting the ambient temperature is provided, and the control means controls the fan not to operate when the ambient temperature detected by the temperature sensor is equal to or lower than a predetermined value. Sometimes the main heat exchanger and the sub heat exchanger can be prevented from freezing.

  In the hot water supply apparatus of the present invention, the control means holds the open / close lid substantially closed by the stopper means after the operation of the hot water supply apparatus is stopped, and controls the fan to operate for a predetermined time to blow air to the surface of the auxiliary heat exchanger. The drain attached to the surface of the auxiliary heat exchanger by the air blown from the fan is dropped and the surface of the auxiliary heat exchanger is dried, and the dropped drain is discharged to the drainage channel via the drain receiver. is there.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, a water heater 1 includes a water heater body 2, a gas supply pipe 40 that supplies fuel gas to the water heater body 2, a water supply pipe 41 that supplies water to the water heater body 2, A hot water discharge pipe 42 for discharging hot water from the main body 2, a drainage channel 43 for discharging drain generated in the auxiliary heat exchanger 7 during the recovery of latent heat, and a neutralizer 44 for neutralizing drainage discharged from the drainage channel 43, An operation panel 47 for operating the hot water supply apparatus 1 and a control unit 48 (C / U) as control means for controlling the entire hot water supply apparatus 1 are provided.

  The gas supply pipe 40 is connected to the gas supply port of the gas supply source and extends to the burner 5. One end of the water supply pipe 41 is connected to a water supply port connected to the water pipe, and the other end is connected to the auxiliary heat exchanger 7. One end of the tapping pipe 42 is connected to the main heat exchanger 6 and the other end is connected to a tapping port, and hot water is supplied from the tapping port to each facility such as a kitchen and a bath.

The drainage channel 43 extends from the lower end portion of the drain receiver 8 and is connected to the neutralizer 44. The drain that has dropped from the surface of the auxiliary heat exchanger 7 is discharged to the drainage channel 43 through the drain receiver 8, Introduced into the sump 44. The neutralizer 44 is filled with calcium carbonate as a neutralizing agent for neutralizing the drain, and the drain introduced from the drain receiver 8 through the drainage channel 43 passes through the calcium carbonate in the neutralizer 44. The neutralization process is performed by passing at low speed, and the drain after the neutralization process is discharged to a sewer or the like through a drain pipe 45 connected to the lower end of the neutralizer 44.
Further, a drain pipe 46 for draining is connected to the side where the drain is introduced at the lower end of the neutralizer 44.

Next, the water heater body 2 will be described.
As shown in FIGS. 1 and 2, the water heater main body 2 includes a main body case 3 and an exhaust cover 20. A combustion chamber 4 is formed in the main body case 3. The combustion chamber 4 is provided with a burner 5 for burning fuel, a main heat exchanger 6 for recovering sensible heat from the combustion gas of the burner 5, and the like. .

  In the main body case 3, the upper end portion includes a sub heat exchanger 7 that recovers latent heat in addition to sensible heat that could not be recovered by the main heat exchanger 6, and sub heat exchange by latent heat recovery in the sub heat exchanger 7. A drain receiver 8 that receives drain generated on the surface of the vessel 7, an opening / closing lid 9 that suppresses the exhaust gas from flowing into the exhaust passage 21, and the like are provided. A fan 12 that supplies combustion air to the burner 5 and a temperature sensor 13 that detects the ambient temperature are provided at the lower end of the main body case 3.

An auxiliary heat exchanger 7 having a plurality of water pipes 7 a is disposed on the upper end member in the main body case 3, and a drain receiver 8 is provided below the auxiliary heat exchanger 7. Here, when the latent heat is recovered by the auxiliary heat exchanger 7, condensed drain adheres to the surfaces of the plurality of water tubes 7 a of the auxiliary heat exchanger 7.
The left and right width of the drain receiver 8 in FIG. 1 is formed to be approximately the same as the left and right width of the main body case 3, and the front and rear length of the drain receiver 8 in FIG. 1 is smaller than the front and rear length of the main body case 3. A combustion gas passage 14 is formed between the rear wall 8 a of the drain receiver 8 and the rear wall of the main body case 3. A combustion gas supply port 15 is formed between the vertical wall 3 a extending from the upper wall of the main body case 3 and the rear wall 8 a of the drain receiver 8, and the combustion gas sent from the combustion chamber 4 passes through the combustion gas passage 14. It passes through and is introduced into the auxiliary heat exchanger 7 from the combustion gas supply port 15 toward the front.

  Here, since the combustion gas passage 14 and the combustion gas supply port 15 are configured to be narrower than the combustion chamber 4, the combustion gas flowing from the combustion chamber 4 increases the flow velocity and increases the auxiliary heat exchanger 7. It flows toward. Therefore, the drain adhering to the water pipe 7a of the auxiliary heat exchanger 7 can be reliably blown off and dropped. In the main body case 3, an exhaust gas discharge port 16 communicating with the exhaust passage 21 is provided on the front side of the auxiliary heat exchanger 7.

  As shown in FIGS. 2 and 3, the exhaust gas discharge port 16 is provided with a circular opening / closing lid 9 when viewed from the front, and the opening / closing lid 9 rotates around the rotation shaft 11 and the rotation shaft 11. It is comprised with the rotation lid 10. The rotary shaft 11 is incorporated slightly above the middle portion of the rotary lid 10, and is configured such that the lower weight of the rotary lid 10 is heavier than the upper weight of the rotary shaft 11. Are respectively inserted through holes in the peripheral wall of the exhaust gas discharge port 16. Therefore, when the fan 12 is blown, as shown by a two-dot chain line in FIG. 2, the rotary lid 10 is rotated counterclockwise by the exhaust gas to be in an open state, and when the fan 12 is stopped, it is indicated by a solid line in FIG. As described above, the rotating lid 10 rotates clockwise by its own weight and is almost closed.

  Here, the rotary lid 10 is formed to have a smaller size than the exhaust gas discharge port 16, and a slight gap is formed between the rotary lid 10 and the peripheral wall of the exhaust gas discharge port 16 when the rotary lid 10 is closed. Therefore, a part of the exhaust gas is discharged from the exhaust gas discharge port 16 to the exhaust passage 21. In addition, by making the rotary lid 10 substantially closed, there is also an effect of suppressing intrusion of rainwater or outside air (cold air).

  As shown in FIG. 2, the exhaust cover 20 is attached to the upper end portion of the main body case 3, and the exhaust for discharging the exhaust gas to the outside by the exhaust cover 20 and the main body case 3 at the portion where the exhaust cover 20 is attached. A passage 21 is formed. At the upper end of the exhaust cover 20, an exhaust port 22 for exhausting exhaust gas that has passed through the exhaust passage 21 is provided. In the exhaust passage 21, a stopper mechanism 23 (stopper means) that holds the open / close lid 9 in a substantially closed state in response to a command from the control unit 48 is provided near the exhaust gas discharge port 16.

  As shown in FIG. 4, the stopper mechanism 23 includes a case 24, a ring-shaped electromagnet coil 25, a stopper 26, and a lid member 29, and the stopper 26 is moved downward by a command from the control unit 48. It is configured to be switchable between a position and an upper operating position. An electromagnet coil 25 is disposed in the case 24, a stopper 26 is disposed in the ring-shaped space 30 of the electromagnet coil 25, and the lid member 29 so that the stopper 26 can protrude from the hole 29 a of the lid member 29. Is fixed to the upper end of the case 24.

  The stopper 26 is configured by fixing a permanent magnet 27 having an N pole at the upper end and an S pole at the lower end to the upper surface of the pedestal 28, and no magnetic force is generated in the ring-shaped space 30 of the electromagnet coil 25 when not energized. As shown by the solid line in FIG. 4, the stopper 26 is located at the lower original position. When a command is received from the control unit 48, the electromagnet coil 25 is energized to generate an upward magnetic force in the ring-shaped space 30, and the stopper 26 is lifted upward as shown by a two-dot chain line in FIG. By switching to the position, the open / close lid 9 is held substantially closed.

  A control unit 48 having a microcomputer is electrically connected to an operation panel 47, a fan 12, a temperature sensor 13, a stopper mechanism 23, and the like. This control unit 48 is an operation stop switch provided on the operation panel 47. Is controlled so as to switch the stopper 26 of the stopper mechanism 23 to the operating position and hold the open / close lid 9 in a substantially closed state based on the operation stop signal transmitted by the user. After the stop, the fan 12 is operated for a predetermined time (for example, 5 minutes) and controlled so as to blow air to the surface of the water pipe 7a of the auxiliary heat exchanger 7. Here, “after operation stop” means a period in which drain generated on the surface of the auxiliary heat exchanger 7 is stuck due to surface tension after the operation of the water heater 1 is stopped, immediately after the operation stop or the operation stop. The time is not particularly specified, such as within a certain period of time immediately after. In addition, the control unit 48 performs control so that the fan 12 is not operated when the ambient temperature detected by the temperature sensor 13 is a predetermined value or lower (for example, 0 ° C. or lower).

  Next, a flowchart of the above-described fan and stopper mechanism control executed by the control unit 48 will be described with reference to FIG. In the figure, Si (i = 1, 2,...) Indicates each step. It is assumed that the program for realizing the fan and stopper mechanism control is stored in the ROM of the microcomputer of the control unit 48.

  This fan and stopper mechanism control program is started when an operation switch provided on the operation panel 47 is operated. First, whether or not the operation stop switch is operated by the user and an operation stop signal is received. Is determined (S1), and the operation stop switch is operated (S1; Yes), the timer TM is reset and started (S2). However, if the operation stop switch is not operated (S1; No), the process returns to the start.

  Next, the detected temperature T of the temperature sensor 13 is read (S3), it is determined whether or not the detected detected temperature T is 0 ° C. or higher (S4), and the detected temperature T is 0 ° C. or higher ( (S4; Yes), the electromagnet 25 is energized, the stopper 26 is switched from the original position to the operating position (S5), and the opening / closing lid 9 is held in a substantially closed state, and then the fan 12 is energized to operate the fan 12. (S6), the air is blown to the surface of the water pipe 7a of the auxiliary heat exchanger 7, and the drain attached to the surface of the water pipe 7a is dropped to dry the surface of the water pipe 7a. However, when the detected temperature T is 0 ° C. or lower (S4; No), the execution of this control program is terminated without operating the fan 12.

  Next, it is determined whether or not 5 minutes or more have elapsed since the fan 12 was operated (S7). If 5 minutes or more have elapsed (S7; Yes), energization of the drive circuit of the fan 12 is stopped and the fan 12 is stopped. (S8), the energization of the electromagnet 25 is stopped, the stopper 26 is returned from the operating position to the original position (S9), and the execution of this control program is terminated. However, if it is less than 5 minutes (S7; No), S7 is repeatedly executed.

Next, the operation and effect of the hot water supply apparatus 1 described above will be described.
After the operation of the hot water supply device 1 is stopped, the stopper 26 is switched to the operating position by the control unit 48 to keep the open / close lid 9 in a substantially closed state, and the fan 12 is operated for 5 minutes to blow air to the surface of the auxiliary heat exchanger 7. The drain attached to the surface of the water pipe 7a of the auxiliary heat exchanger 7 is dropped by blowing air from the fan 12, and the surfaces of these water pipes 7a are dried. Thereby, the drain adhering to the surface of the water pipe 7a of the auxiliary heat exchanger 7 during latent heat recovery is removed, and corrosion of the auxiliary heat exchanger 7 due to the drain can be prevented. At this time, the drained drain is discharged to the drainage channel 43 through the drain receiver 8, so that the neutralization process is performed by the neutralizer 44 provided on the downstream side of the drainage channel 43 and then the drain is discharged to the outside. Can do. It should be noted that there is no problem if the dropped drain is discharged directly to the drainage channel 43 without passing through the drain receiver 8, and the present invention includes such a case.

  As described above, after the operation of the hot water supply device 1 is stopped by the control unit 48, the fan 12 is operated for 5 minutes to blow air to the surface of the water pipe 7 a of the auxiliary heat exchanger 7, and the drain adhering to the surface of the water pipe 7 a is dropped. Since the surface of the water pipe 7a is dried, the drain adhering to the surface of the water pipe 7a of the auxiliary heat exchanger 7 during latent heat recovery can be completely removed, and corrosion of the auxiliary heat exchanger 7 can be prevented. At this time, since the combustion gas passage 14 and the combustion gas supply port 15 are narrower than the combustion chamber 4, the combustion gas flowing from the combustion chamber 4 increases in flow rate and flows toward the auxiliary heat exchanger 7. Thus, the drain adhering to the auxiliary heat exchanger 7 can be reliably blown off and dropped. Further, since the drained drain is discharged to the drainage channel 43 through the drain receiver, the drain can be discharged to the sewer after performing the neutralization process by the neutralizer 44, and does not adversely affect the environment.

Furthermore, since the opening / closing lid 9 that suppresses the outflow of the exhaust gas to the exhaust passage 21 is provided, when the fan 12 is operated for 5 minutes after the hot water supply device 1 is stopped, the opening / closing lid 9 is substantially closed. It is possible to prevent most of the drain from being blown off by the fan 12 and flowing out into the exhaust passage 21, and the drain is not scattered into the air through the exhaust passage 21.
The open / close lid 9 is a rotary lid 10 that rotates about the rotary shaft 11 and is configured to be opened when the fan 12 is blown and is substantially closed when the fan 12 is stopped. Sometimes, the rotary lid 10 is almost closed, and rainwater or the like can be prevented from entering the hot water supply apparatus 1 through the exhaust passage 21.

When the fan 12 is operated by the control unit 48, the stopper mechanism 23 that holds the open / close lid 9 in a substantially closed state is provided. Therefore, when the fan 12 is operated for 5 minutes after the hot water supply device 1 is stopped, Can be reliably prevented from flowing out into the exhaust passage 21, and the drain does not scatter into the air via the exhaust passage 21.
Further, a temperature sensor 13 for detecting the ambient temperature is provided, and the control unit 48 controls the fan 12 not to operate when the ambient temperature detected by the temperature sensor 13 is 0 ° C. or lower. The freezing of the main heat exchanger 6 and the auxiliary heat exchanger 7 can be prevented without introducing (cold air) into the hot water supply device 1.

Next, a modified example in which the above embodiment is partially modified will be described.
1] Instead of the opening / closing lid 9, an opening / closing lid 9A shown in FIGS. In this case, the rotary shaft 11 is incorporated in the middle portion of the rotary lid 10, and both end portions of the rotary shaft 11 are inserted through holes in the peripheral wall of the exhaust gas discharge port 16. A weight 50 is provided in the vicinity of the lower end portion of the rotating lid 10, and when the fan 12 is operated, as shown by a two-dot chain line in FIG. At the time of stopping 12, as shown by a solid line in FIG. 7, the rotating lid 10 is configured to rotate clockwise by the weight of the weight 50 so as to be almost closed.

  2] As shown in FIG. 8, the stopper mechanism 23A may be configured so that the opening / closing lid 9 is opened when energized and the opening / closing lid 9 is substantially closed when de-energized. In the stopper mechanism 23A, an electromagnet coil 25A that generates a downward magnetic force in the ring-shaped space 30 when energized is provided, and a steel stopper 26A made of a magnetic material and a coil spring 51 are provided instead of the permanent magnet 27. In this case, the stopper 26A is switched to the lower operating position against the spring force of the coil spring 51 by the downward magnetic force generated in the ring-shaped space 30 of the electromagnet coil 25A when energized, and the open / close lid 9 is opened. When energized, the stopper 26A is switched to the upper original position by the biasing force of the coil spring 51 so that the open / close lid 9 is substantially closed.

  3] As shown in FIGS. 9 and 10, the stopper mechanism 23 </ b> B may be configured so that the open / close state of the open / close lid 9 can be switched by driving the servo motor 52. In this case, the stopper mechanism 23B includes a servo motor 52, a worm gear 53 that rotates when the servo motor 52 is driven, a worm wheel 54 that meshes with the worm gear 53, and a shaft 55 that can rotate integrally with the worm wheel 54. The stopper 56 is fixed and has a semicircular shape when viewed from the front. The stopper mechanism 23B is configured to hold the opening / closing lid 9 between the stopper 56 and the worm wheel 54 to hold the closing state of the opening / closing lid 9 and drive the servo motor 52 via the worm gear 53. The wheel 54 and the stopper 56 are integrally rotated by 180 ° from the holding position so that the wheel 54 and the stopper 56 can be switched over to an open position where the opening / closing lid 9 is opened.

4] In the auxiliary heat exchanger 7, ribs are respectively formed along the length direction at the lower ends of the plurality of water pipes 7a so as to promote the fall of the drain adhering to the surfaces of the water pipes 7a. May be.
5] In the above-described embodiment, the present invention is applied to the hot water supply apparatus 1 in which the exhaust port 22 is provided with the exhaust port 22 at the upper end, but the exhaust water is exhausted from the front by providing the exhaust port at the front end of the exhaust cover 20. It is also applicable to.
6) In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. .

It is a schematic block diagram of the hot water supply apparatus which concerns on the Example of this invention. It is a longitudinal cross-sectional view of a hot water supply apparatus. It is a front view around an opening / closing lid. It is a longitudinal cross-sectional view of a stopper mechanism. It is a flowchart of a fan and stopper mechanism control. FIG. 4 is a diagram corresponding to FIG. 3 of a modified example. It is a longitudinal cross-sectional view of the opening-and-closing lid periphery in a modification. FIG. 6 is a diagram corresponding to FIG. 4 of a modified example. It is a side view of the stopper mechanism in a modification. It is a front view of the stopper mechanism in a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot-water supply apparatus 5 Burner 6 Main heat exchanger 7 Sub heat exchanger 8 Drain receptacle 9, 9A Opening / closing lid 10 Rotating lid 12 Fan 13 Temperature sensor 21 Exhaust passage 23, 23A, 23B Stopper mechanism 43 Drainage channel 48 Control unit

Claims (5)

In addition to sensible heat that could not be recovered by the main heat exchanger, a burner that burns fuel, a fan that supplies combustion air to the burner, a main heat exchanger that recovers sensible heat from the combustion gas of the burner Sub-heat exchanger that recovers latent heat, exhaust passage that exhausts exhaust gas after heat recovery in the sub-heat exchanger, and drain generated on the surface of the sub-heat exchanger due to latent heat recovery in the sub-heat exchanger In a hot water supply apparatus comprising a drain receiver that receives the drain and a drainage channel that discharges the drain received by the drain receiver,
A control means for controlling the fan to operate for a predetermined time after the operation of the water heater is stopped and to blow air to the surface of the auxiliary heat exchanger;
The drain attached to the surface of the auxiliary heat exchanger by the air blown from the fan is dropped and the surface of the auxiliary heat exchanger is dried, and the dropped drain is discharged to the drainage channel via the drain receiver. A hot water supply device.   The hot water supply apparatus according to claim 1, further comprising an open / close lid that suppresses an outflow of exhaust gas to the exhaust passage.   3. The open / close lid is a rotary lid that rotates about a rotation shaft, and is configured to be an open state when the fan is blown and close when the fan is stopped. The hot water supply device described.   The hot water supply apparatus according to claim 3, further comprising stopper means for holding the open / close lid in a substantially closed state when the fan is operated by the control means. It has a temperature sensor that detects the ambient temperature,
The hot water supply apparatus according to any one of claims 1 to 4, wherein the control means performs control so that the fan is not operated when the ambient temperature detected by the temperature sensor is equal to or lower than a predetermined value.

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