JP2013210115A - Water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater which excels in economic efficiency by reducing an amount of water and hot water to be discarded by suppressing the number of times re-heating pipes are cleaned.SOLUTION: A water heater which has a configuration of being capable of supplying drain water produced at a heat exchanger unit 1 to a pipe 23 for discharging the drain water through pipes 8 and 9 for re-heating water inside a bathtub B, includes a pipe 28 for supplying clean hot water to the pipes 8 and 9 for re-heating, and a water discharging detecting unit 27 which detects discharging of the hot water in the bathtub B, and on the condition that the water discharging detecting unit 27 detects discharging of water in the bathtub B, after the drain water stored in a drain tank 16 is supplied and discharged to the pipe 23 for discharging the drain water through the pipes 8 and 9 to re-heating, clean water is supplied to the pipes 8 and 9 for re-heating to clean the pipes 8 and 9 for re-heating, so that it is possible to eliminate cleaning of the pipes 8 and 9 for re-heating which would be only intended to clean remaining hot water and reduce water to be discarded.

Description

  The present invention relates to a hot water supply apparatus, and more specifically, includes a secondary heat exchanger that heats hot water supplied to the primary heat exchanger using latent heat contained in exhaust gas of combustion gas that heats the primary heat exchanger. The present invention relates to a technique for draining drain water generated in a secondary heat exchanger in a hot water supply apparatus.

  Conventionally, in a hot water supply device, hot water supplied to a primary heat exchanger is obtained using latent heat contained in exhaust gas of combustion gas that heats a primary heat exchanger that generates hot water used for hot water supply or bathing of a bathtub. Some have been provided with a secondary heat exchanger for heating.

  In this type of hot water supply apparatus, since acidic drain water is generated in the secondary heat exchanger, it is necessary to discharge the drain water to the outside. As a configuration for this purpose, a bathtub and a hot water supply apparatus are used for refilling the bath. There is a configuration in which drain water is discharged to the outside by using a pipe (fired pipe) provided between (see, for example, Patent Document 1).

  When adopting a configuration in which drain water is discharged to the outside by using a recirculation pipe in this way, acidic drain water remains attached in the retreat pipe after drain water is discharged. After discharging, clean water is dropped into the recirculation piping from the plumbing of hot water into the bathtub communicating with the recirculation piping, and the drain water remaining in the recirculation piping is washed away Water washing function).

  On the other hand, with regard to such a hot water supply device, recently, when drainage of the remaining hot water in the bathtub is detected, the remaining hot water (hot water) remaining in the reheating pipe is washed away with clean hot water (remaining hot water washing function). There is also a proposal with the added. This remaining hot water cleaning function is similar to the drain water cleaning function described above, by dropping clean hot water into the reheating pipe from the hot water dropping pipe to the bathtub communicating with the reheating pipe, and into the reheating pipe. This is a function of washing away (removing) the remaining hot water remaining on the surface, and this function functions independently of the drain water cleaning function.

JP 2009-270798 A

  However, in such a hot water supply device having a drain water cleaning function and a remaining hot water cleaning function, these functions are operated independently of each other. Clean hot water will be supplied to the reheating pipe. Therefore, for example, when the drain water drainage function is activated within a short time after the operation of the remaining hot water cleaning function is completed, 2 drops of clean hot water (supply) into the recirculation pipe within a short time. This was repeated many times, and the amount of waste water (waste water) accompanying the cleaning of the reheating pipes increased, which was uneconomical.

  The present invention has been made in view of such problems, and the object of the present invention is to reduce the amount of waste water and waste water by suppressing the number of times the recirculation pipe is washed, thereby making it economical. The object is to provide an excellent water heater.

  In order to achieve the above object, a hot water supply apparatus according to claim 1 of the present invention is provided with piping for reheating between a bathtub and drain water generated in a heat exchanger section for reheating. In a hot water supply apparatus having a configuration capable of supplying drain water discharge piping via piping, hot water supply means for supplying clean hot water to the reheating piping, and detection of drainage of hot water in the bathtub A drainage detecting means and a control section, the control section draining the drain water through the reheating pipe on the condition that the drainage detection means detects the drainage of hot water in the bathtub. A control structure is provided for performing processing for supplying clean hot water to the piping for replenishment by the hot water supply means and cleaning the piping for replenishment after performing processing for supplying the piping for discharge. It is characterized by.

  That is, in this hot water supply apparatus, drain water is discharged through a recirculation pipe on the condition that the drainage detection means detects the drainage of hot water (so-called remaining hot water) in the bathtub. Subsequently, clean hot water is supplied to the piping for reheating, and the piping for reheating is cleaned, so that the remaining hot water remaining on the piping for reheating and drain water are cleaned once (hot water supply). By a process of supplying clean hot water to the piping for reheating by means). Therefore, according to this hot water supply apparatus, it is possible to omit the supply of clean hot water to the reheating pipe for the purpose of cleaning only the remaining hot water remaining on the reheating pipe. It is possible to reduce the amount of waste water and waste water that accompanies pipe cleaning.

  Moreover, the hot water supply device according to claim 2 of the present invention is the hot water supply device according to claim 1, wherein a drain water storage tank that stores drain water generated in the heat exchanger section, and the drain water storage tank A water level detecting means for detecting the water level of the drain water storage tank detected by the water level detecting means in addition to detecting the drainage of hot water in the bathtub by the drainage detecting means. On the condition that the water level of the water is equal to or higher than a predetermined water level, the drain water is supplied to the drain water discharge pipe through the reheating pipe, and then the hot water supply means is used for reheating. It is characterized by having a control configuration for performing a process of supplying clean hot water to the pipe and cleaning the inside of the pipe for reheating.

  That is, in the hot water supply apparatus according to the second aspect, drain water generated in the heat exchanger section is stored in the drain water storage tank. Then, if the drainage detection means detects the drainage of hot water in the bathtub and the level of the drain water stored in the drain water storage tank is equal to or higher than the predetermined water level, it passes through a reheating pipe. The drain water thus discharged is discharged, and following this process, clean hot water is supplied to the reheating pipe, and the reheating pipe is cleaned. That is, in this hot water supply apparatus, even if the drainage detection means detects the drainage of the hot water in the bathtub, if the water level in the drain water storage tank is less than the predetermined water level, the drain water is drained through the piping for retreating. No treatment (drain water discharge) is supplied to the water discharge pipe. Therefore, in this case, if the hot water supply device has a remaining hot water washing function, only the remaining hot water remaining on the reheating pipe is washed on condition that the drainage detection means detects the drainage of hot water in the bathtub. For this purpose, clean hot water is supplied to the piping for reheating.

  Therefore, according to this hot water supply apparatus, when the drain water in the drain storage tank is small, drain water is not discharged through the piping for replenishment. The operation can be omitted, and the consumption of the parts that operate along with the drain water discharge process can be suppressed.

  The hot water supply apparatus according to claim 3 of the present invention is the hot water supply apparatus according to claim 2, wherein the predetermined water level is set in the vicinity of a minimum water level detectable by the water level detection means. And

  That is, in the hot water supply apparatus according to claim 3, when the water level in the drain water storage tank is lower than the water level in the vicinity of the lowest water level that can be detected by the water level detecting means, that is, when the drain water storage tank is nearly empty, Drain water is not discharged through the service pipe. Therefore, in this hot water supply apparatus, when there is even a small amount of drain water stored in the drain water storage tank, the drain water is actively discharged along with the hot water discharge from the bathtub, and the piping for reheating following this process is washed. Therefore, it is avoided that the drain water storage tank is filled with drain water.

  Moreover, the hot water supply device according to claim 4 of the present invention is the hot water supply device according to any one of claims 1 to 3, wherein the hot water supply means is provided for filling a bathtub or adding hot water. It is also used as hot water means and / or water injection means provided for adding water to the bathtub.

  That is, in the hot water supply apparatus according to claim 4, the hot water supply means for supplying clean hot water to the reheating pipe is supplied to the hot water pouring means and / or the bathtub provided for filling the bathtub or adding hot water. Since it is also used as the water injection means provided for the additional water, it is not necessary to add a new configuration for cleaning the reheating pipe, and the present invention is applied only by changing the control configuration of the control unit. it can.

  According to the present invention, on the condition that the hot water drainage in the bathtub is detected, the drain water is discharged through the reheating pipe, and subsequently, the reheating pipe is washed. The remaining hot water and drain water remaining on the pipes can be cleaned at a time, and the amount of waste water and waste water accompanying cleaning of the reheating pipes can be reduced, making it economical and efficient. An apparatus can be provided.

It is a block diagram which shows schematic structure of the hot water supply apparatus with which this invention is applied. It is a flowchart which shows an example of the washing | cleaning procedure of drainage of the drain water in the same hot-water supply apparatus, and a follow-up piping.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a schematic configuration of a hot water supply apparatus to which the present invention is applied. The hot water supply apparatus shown in FIG. 1 is a hot water supply apparatus (bath water heater) having a hot water supply function for supplying hot water to a hot water tap such as a curan (not shown) and a bath replenishment function for boiling hot water in the bathtub B. In connection with the present invention, this hot water supply apparatus has a function of discharging drain water generated in the heat exchanger section 1 described later using a piping for replenishing the bath, and after discharging drain water. And a function of cleaning the reheating pipe.

  The heat exchanger section 1 of this hot water supply apparatus includes a hot water supply heat exchanger section 1a that mainly generates hot water for hot water supply and a reheating heat exchanger section 1b that mainly generates hot water for bathing. Each of the heat exchanger units 1a and 1b for hot water supply and reheating is provided with a gas burner 2 as a heat source. Each of the heat exchanger units 1a and 1b is composed of a latent heat recovery type heat exchanger, and each of the heat exchanger units 1a and 1b has a primary heat exchanger and a secondary heat exchange, although not shown. And a vessel.

  Specifically, the heat exchanger section 1a for hot water supply heats and raises the temperature of water supplied from the inlet pipe 3 connected to a water source such as city water, and is heated by the combustion gas of the burner 2. A heat exchanger and a secondary heat exchanger that uses latent heat contained in the exhaust gas of the combustion gas that heated the primary heat exchanger, and water supplied from the water inlet pipe 3 passes through the secondary heat exchanger. After being supplied to the primary heat exchanger, it is configured to be supplied from the primary heat exchanger to the hot water discharge pipe 4 connected to the hot water tap. In the illustrated hot water supply apparatus, a bypass pipe 5 is provided between the water inlet pipe 3 and the hot water outlet pipe 4 so that water can be supplied from the water inlet pipe 3 to the hot water outlet pipe 4 by bypassing the heat exchanger section 1a. The configuration is shown, and the bypass pipe 5 is provided with a bypass valve 6 for controlling the flow rate in the bypass pipe 5.

  On the other hand, the reheating heat exchanger section 1b heats and raises the hot water supplied from the bathtub B, and is heated by the combustion gas of the burner 2 in the same manner as the heat exchanger section 1a for hot water supply described above. A primary heat exchanger and a secondary heat exchanger that uses latent heat contained in the exhaust gas of the combustion gas that heated the primary heat exchanger, and the hot water supplied from bathtub B is a secondary heat exchanger. Then, after being supplied to the primary heat exchanger, it is configured to be supplied to the bathtub B from the primary heat exchanger.

  More specifically, the bathtub B is provided with suction of hot water in the bathtub B and discharge of hot water heated by the heat exchanger portion 1b for heating into the bathtub B when the bath is refilled. A circulation adapter 7 is provided, and a suction port (not shown) of the circulation adapter 7 has a tip at the water inlet side of the heat exchanger section 1b for reheating, that is, a secondary heat exchanger for reheating. A reflow pipe 8 connected to the water inlet side of the circulation adapter 7 is connected, and the discharge port (not shown) of the circulation adapter 7 has a tip at the hot water side of the heat exchanger section 1b for reheating, that is, for reheating. An outlet pipe 9 connected to the hot water outlet side of the primary heat exchanger is connected.

  Then, the hot water sucked from the suction port of the circulation adapter 7 is supplied to the bath return pipe 8 via the bath return pipe 8, the heat exchanger section 1 b for catching, and the bath return pipe 9. A circulation pump 11 for performing forced circulation discharged from the discharge port of the circulation adapter 7 and a water flow detector (water flow switch in the illustrated example) 12 for detecting the presence or absence of this forced circulation are provided. A flow path in which hot and cold water is forcibly circulated when the bath is refilled, that is, the bath return pipe 8, the heat exchanger section 1b for reheating, and the bath pipe 9 constitute a reheating pipe (retreating pipe). doing.

  Reference numeral 13 denotes a neutralizer for neutralizing acidic drain water generated in each of the secondary heat exchangers of the hot water supply and reheating heat exchanger sections 1a and 1b. The neutralizer 13 has one end connected via a pipe 14 to a recovery mechanism (not shown) that recovers drain water generated in the secondary heat exchanger of each of the heat exchanger units 1a and 1b. The end is connected to a drain tank (drain water storage tank) 16 for storing drain water neutralized by the neutralizer 13 and a pipe 15, and the acidic drain water generated in the secondary heat exchanger is Sequentially, it is supplied to the neutralizer 13 via the pipe 14, neutralized by the neutralizer 13, and stored in the drain tank 16.

  The drain tank 16 is provided with a water level electrode 17 as means for detecting the level of drain water in the tank, and information on the water level of the drain water detected by the water level electrode 17 is given to the control unit 100 of the hot water supply apparatus. It is like that. Here, the water level electrode 17 detects at least the electrode 17a for detecting that the drain tank 16 is full (or a state close to full water) and the drain tank 16 being empty (or a state close to empty). Electrode 17b. Specifically, electrodes 17a and 17b having different vertical lengths are disposed in the drain tank 16, and when the water level in the drain tank 16 is higher than the lower end of the short electrode 17a, the controller 100 causes the drain tank 16 to The drain tank 16 is determined to be empty (or nearly empty) when the water level is less than the lower end of the long electrode 17b. Has been.

  In the present embodiment, the case where the water level electrode 17 is used as the water level detecting means for detecting the water level in the drain tank 16 has been shown. However, the water level in the drain tank 16 (particularly, in relation to the present invention, the drain tank 16 It is also possible to use a sensor other than the water level electrode 17, for example, a pressure sensor, as long as it is a sensor that can detect whether the sensor is empty or close to the sky.

  And in the hot water supply apparatus which concerns on this invention, the piping 18 is connected to the lower part (for example, bottom face of the drain tank 16) regarding the drain water after neutralization stored in the drain tank 16, and the drain tank 16, The end of the pipe 18 is connected to the bath return pipe 8 via a three-way valve 20 (hereinafter referred to as “the instrument-side three-way valve”), and drain water in the drain tank 16 is passed through the instrument-side three-way valve 20. It is configured so that it can be supplied to the return pipe 8. Here, the three-way valve 20 on the side of the instrument is disposed on the upstream side of the circulation pump 11, that is, on the circulation adapter 7 side in the bath return pipe 8. Further, on the further upstream side of the three-way valve 20, a two-way valve 21 having a structure capable of opening and closing the flow path of the bath return pipe 8 is provided.

  In addition, a drain water drain pipe 23 having one end connected to a drain pipe 24 communicating with sewage is connected to a three-way valve 22 (hereinafter referred to as “three-way on the bathtub side” in connection with drain water discharge. Connected through a valve). This bathtub-side three-way valve 22 is provided on the downstream side of the throat pipe 9, that is, in the vicinity of the circulation adapter 7. As will be described later, the neutralized drain supplied through the throat pipe 9. The water is configured to be supplied to the drain pipe 24 via the drain water discharge pipe 23.

  Further, in relation to the drain water discharge, the hot water supply apparatus of the present embodiment is provided with a waste water detection means 27 for detecting drainage of hot water (for example, remaining hot water after bathing) in the bathtub B. This drainage detection means 27 is composed of a sensor for detecting the completion of drainage of hot water in the bathtub B (or the state immediately before the drainage is completed). In the illustrated example, the drainage of the bathtub B A sensor (for example, a water flow switch) that detects the presence / absence of water flowing through the pipe 26 (that is, the presence / absence of drainage of hot water from the bathtub B) is used for the pipe 26 that connects the mouth 25 and the drain pipe 24. In this case, the control part 100 of the hot-water supply apparatus mentioned later detects the start of drainage of the bathtub B when the water flow switch that constitutes the waste water detection means 27 detects the water flow (there is a water flow). And it is comprised so that the completion | finish of drainage of the bathtub B may be detected when it stops detecting a water flow (it changed from the water flow with no water flow).

  By the way, as this waste_water | drain detection means 27, besides using the sensor which detects the presence or absence of the waste_water | drain from the bathtub B like illustration, the water level sensor which detects the water level of the hot water in the bathtub B can also be used, for example. In this case, the controller 100 of the hot water supply apparatus monitors the water level detected by the water level sensor, detects the start of drainage when the amount of water level decrease per unit time exceeds a predetermined value, and the detected water level is the water level. It is comprised so that it may judge that the drainage of the hot water in the bathtub B is a state immediately before completion by falling below the minimum water level detectable with a sensor.

  28 denotes hot water for cleaning the reheating pipe (the bath return pipe 8, the heat exchanger section 1b for reheating, and the forward pipe 9) performed after the drain water discharge process described later, that is, clean water for cleaning. This is a pipe for supplying hot water, and in this embodiment, as this clean hot water, water supplied to the inlet pipe 3 (water supplied from a water source such as city water) is used. Show.

  Specifically, this pipe 28 is connected between the circulation pump 11 in the return pipe 8 and the three-way valve 20 on the appliance side from the upstream side of the branch point with the bypass pipe 5 in the inlet pipe 3. The water supplied to the water pipe 3 can be supplied to the return pipe 8. The pipe 28 is provided with a water electromagnetic valve 29 capable of blocking the flow path of the pipe 28, and the water electromagnetic valve 29 is opened and closed to supply / stop water to the bath return pipe 8. It can be controlled. That is, in the hot water supply apparatus of the present embodiment, the hot water supply means for supplying clean hot water to the recirculation pipe is constituted by the water inlet pipe 3 connected to the water source, the pipe 28 and the water electromagnetic valve 29.

  In the present embodiment, the hot water supply means is configured to supply the water supplied to the inlet pipe 3 to the recirculation pipe. However, the hot water supply means may be hot water as long as it can supply clean hot water. For example, the hot water discharge pipe 4 and the bath return pipe 8 are connected by piping, and an electromagnetic valve for opening and closing the flow path corresponding to the water electromagnetic valve 29 is provided in the piping. It is also possible to configure so that hot water supplied from the hot water discharge pipe 4 can be supplied to the reheating pipe.

  Therefore, for example, the hot water supply device opens and closes the pouring means for filling the bathtub B and adding hot water (specifically, the pipe connecting the outlet pipe 4 and the return pipe 8 and the flow path of the pipe). In the case of having a solenoid valve), the pouring means can also be used as the hot water supply means. Moreover, when it has the water injection means for the addition water to the bathtub B (specifically, the piping which connects the hot-water pipe 4 and the bath return pipe 8, and the electromagnetic valve which opens and closes the flow path of the said piping) In this case, the water injection means can also be used as hot water supply means. Furthermore, when it has a pouring means and a water pouring means, either one or both of them can be used as the hot water supply means. As described above, in the hot water supply apparatus having functions such as filling the bathtub B, adding hot water, and adding water, the hot water pouring means and / or the water pouring means provided to realize these functions are used as the hot water supply means. Thus, the present invention can be applied without separately providing hot water supply means.

  Reference numeral 100 denotes a control unit of the hot water supply device. The control unit 100 includes a microcomputer for controlling each part of the hot water supply device, and various sensors (for example, a water flow switch 12, Based on information given from the water level electrode 17, drainage detection means 27, etc., or a control signal given from a remote controller (remote control device) of a hot water supply device (not shown), each part of the hot water supply device (for example, bypass valve 5, circulation pump) 11, the three-way valve 20 on the appliance side, the two-way valve 21, the three-way valve 22 on the bathtub side, the water electromagnetic valve 29, and the like) are controlled.

Next, the operation of the hot water supply apparatus according to the present invention will be described.
The hot water supply apparatus of the present invention has a hot water supply function for supplying hot water to a hot water tap such as a curan and a hot water replenishment function for boiling the hot water in the bathtub B as described above, and the heat exchanger section 1 (specifically, Has a function of discharging drain water generated in the secondary heat exchanger) using a reheating pipe and a function of cleaning the reheating pipe after drain water is discharged.

A. Hot water supply function:
The hot water supply function is a function that heats and raises the temperature of the water supplied from the inlet pipe 3 by the heat exchanger section 1a for hot water supply, generates hot water, discharges the generated hot water from the outlet pipe 4 and supplies it to the hot water tap. is there. In addition, since the hot water supply function in the hot water supply apparatus is publicly known, a detailed description of the hot water supply function is omitted here, but as described above, the hot water supply apparatus shown in the present embodiment has latent heat in the heat exchanger 1a for hot water supply. Since a recovery type heat exchanger is used, drain water is generated in the secondary heat exchanger during operation of the hot water supply function (when the hot water supply burner 2 is combusting), and the drain water is recovered from the recovery mechanism. While being supplied to the neutralizer 13 through the pipe 14, the neutralized drain water is stored in the drain tank 16 through the pipe 15. During the operation of the hot water supply function, the water electromagnetic valve 29 is closed, and the supply of water from the inlet pipe 3 to the return pipe 8 is shut off.

B. Furano rebellion function:
The bathing function is a function of boiling hot water in the bathtub B to a set temperature set by a remote controller or the like. When this function is activated, the control unit 100 is configured to flow the flow path of the two-way valve 21. Is opened, the flow path to the pipe 18 (drain tank 16) in the three-way valve 20 on the appliance side is closed, the flow path connecting the two-way valve 21 and the circulation pump 11 is opened, and the pipe in the three-way valve 22 on the bathtub side is further opened. 23, the flow path connecting the heat exchanger section 1b for reheating and the discharge port of the circulation adapter 7 is opened, and the circulation pump 11 is operated. As a result, when water flows in the reheating pipe and the water flow switch 12 detects this water flow, the control unit 100 burns the reheating burner 2 and heats the hot water by the reheating heat exchanger 1b. Start heating. The heating temperature rise by the reheating heat exchanger section 1b is performed until the hot water in the bathtub B reaches a set temperature.

  Even in this reheating function, since the latent heat recovery type heat exchanger is used for the reheating heat exchanger section 1b, the reheating function is in operation (the reheating burner 2 is in combustion). In the secondary heat exchanger, drain water is generated, and the drain water is supplied from the recovery mechanism to the neutralizer 13 via the pipe 14, and the drain water after neutralization is drained to the drain tank via the pipe 15. 16 is stored. Further, the water electromagnetic valve 29 is closed even during the operation of the reheating function, and the supply of water from the inlet pipe 3 to the return pipe 8 is shut off.

C: Drain water discharge and reheating piping cleaning function Next, the drain water discharging function and reheating piping cleaning function will be described with reference to FIG.

  Since the hot water supply apparatus shown in the present embodiment is configured to store drain water generated in the secondary heat exchanger of the heat exchanger unit 1 in the drain tank 16 as described above, the drain tank 16 is configured to be drain water. It is necessary to drain the drain water stored in the tank 16 before it becomes full. For this reason, in the hot water supply apparatus of this embodiment, the drain water is discharged following the drainage of the remaining hot water (hot water) in the bathtub B after bathing.

  Specifically, when the user opens a drain plug (not shown) that closes the drain port 25 of the bathtub B and starts draining hot water in the bathtub B, the hot water in the bathtub B passes through the pipe 26 from the drain port 25. Therefore, the control unit 100 detects the passage of water through the pipe 26 by the drainage detection means 27 to detect the start of drainage (see step S1 in FIG. 2).

  And when drainage of bathtub B is completed, since water flow to piping 26 stops, control part 100 detects this water flow stop by drainage detection means 27, and detects completion of drainage (refer to Step S2 of Drawing 2). .

  In addition, when the water level sensor which monitors the water level of the bathtub B is used as the waste_water | drain detection means 27, the control part 100 detects the start of drainage from the change of the water level detected with this water level sensor, and detects with a water level sensor. It is determined that drainage of hot water in bathtub B has been completed when the water level below the detectable lower limit water level (to be exact, it is in the state immediately before drainage is complete, but the drain water discharge treatment start condition is drainage Impersonating completion).

  In this way, when the control unit 100 detects completion of drainage of the bathtub B, the control unit 100 next determines whether or not there is drain water in the drain tank 16 (see step S3 in FIG. 2). Here, whether or not there is drain water in the drain tank 16 is determined by a water level detection means (water level electrode) 17 provided in the drain tank 16. In this embodiment, this determination is performed using the electrode 17b that detects that the drain tank 16 is empty (or a state close to empty), and the electrode 17b detects the water level of the drain water (drain tank). If the water level in 16 is higher than the lower end of the electrode 17b, it is determined that there is drain water (stored) in the drain tank 16.

  When it is determined that there is drain water in the drain tank 16, the control unit 100 starts discharging the drain water stored in the drain tank 16 (see step S4 in FIG. 2). That is, the hot water supply apparatus shown in the present embodiment is configured to start the draining process of the drain water in the drain tank 16 on the condition that the draining of the hot water in the bathtub B is completed.

  This drain water discharge process is performed by a route indicated by a one-dot chain line in FIG. Specifically, in the drain water discharge process, the control unit 100 closes the two-way valve 21 and opens a flow path communicating with the pipe 18 (drain tank 16) of the three-way valve 20 on the appliance side. And the bath return pipe 8 in the hot water supply apparatus are in communication with each other, and the flow path communicating with the pipe 23 of the three-way valve 22 on the bathtub side is opened to connect the bath piping 9 and the drain pipe 24 to the circulation pump. 11 is activated. Thereby, the drain water in the drain tank 16 is led from the appliance-side three-way valve 20 to the bathtub-side three-way valve 22 through the bath return pipe 8 in the hot water supply device and the reheating heat exchanger portion 1b. The three-way valve 22 on the bathtub side is supplied to the drain pipe 24 through the pipe 23 (that is, drain water is discharged from the drain pipe 24 through the reheating pipe). At this time, the flow path on the two-way valve two-way 21 side of the instrument-side three-way valve 20 is closed, and since the two-way valve 21 is also closed, the drain water is upstream of the instrument-side three-way valve 20. This means that it does not flow out into the bathtub B via the bath return pipe 8 (mainly the bath return pipe 8 arranged outside the hot water supply device) arranged on the circulation adapter 7 side. .

  During the execution of the drain water discharge process, the water electromagnetic valve 29 is closed, and the supply of water from the inlet pipe 3 to the return pipe 8 is shut off. The drain water is discharged until the drain water in the drain tank 16 runs out (until the drain tank 16 becomes empty). For example, the control unit 100 continues the drain water discharge process until a certain time has elapsed after the water level electrode 17b no longer detects the water level, and when it can be determined that the drain tank 16 is empty, Is finished, and the cleaning process for the next reheating pipe is started (see step S5 in FIG. 2).

  As shown by the two-dot chain line in FIG. 1, this reheating pipe cleaning process is a process of supplying clean hot water to the reheating pipe and washing away drain water adhering to the reheating pipe. Then, the control unit 100 opens the two-way valve 21 and closes the flow path communicating with the pipe 18 (drain tank 16) of the three-way valve 20 on the appliance side so that the communication state between the drain tank 16 and the bottom return pipe 8 is established. The discharge pipe 8 from the circulation adapter 7 to the reheating heat exchanger 1b is brought into a communication state. At this time, the three-way valve 22 on the bathtub side closes the flow path communicating with the pipe 23 to bring the flow-through pipe 9 and the circulation adapter 7 into communication. In this state, the water electromagnetic valve 29 is opened so that clean water supplied to the inlet pipe 3 is supplied to the return pipe 8. Thereby, the clean water supplied to the bath return pipe 8 is drained from the drain port 25 of the bathtub B through the three-way valve 20 on the appliance side, the two-way valve 21 and the suction port of the circulation adapter 7 by the water pressure. Drainage of the tub B through the route (the route in which the return pipe 8 flows backward toward the outside of the hot water supply device), the heat exchanger section 1b for reheating, the three-way valve 22 on the bathtub side, and the outlet of the circulation adapter 7 The water will be drained through the two routes of the route from the mouth 25 to the drain pipe 24 (the forward flow path from the long return pipe 8 to the long forward pipe 9), and the entire area of the reheating pipe is washed away with clean water. And washed. At this time, the circulation pump 11 is in a stopped state without being operated.

  In this embodiment, in the cleaning process of the recirculation pipe, in this embodiment, the three-way valve 22 on the bathtub side is configured to communicate with the forward pipe 9 and the circulation adapter 7. Alternatively, the forward pipe 9 and the pipe 23 may be communicated with each other. In short, the bathtub-side three-way valve 22 may connect either the circulation adapter 7 or the pipe 23 and the forward pipe 9 as long as the reheating pipe is cleaned.

  That is, in the hot water supply apparatus shown in the present embodiment, if the drain water is stored in the drain tank 16 when the drainage detection means 27 detects the drainage of the hot water in the bathtub B, the control unit 100 moves the inside of the drain tank 16. The drain water stored in the tank is supplied to the drain water discharge pipe 23 through the reheating pipe to discharge the drain water, and then the clean water is supplied to the reheating pipe following the drain water discharge. Therefore, if drain water is stored in the drain tank 16, the remaining hot water adhering to the recirculation pipe and the drain water are discharged by using the bathtub B. As a result, the drain water adhering to the reheating pipe can be washed together in one wash, and the reheating pipe only for the purpose of cleaning the remaining hot water remaining on the reheating pipe is cleaned. The can be omitted, it is possible to provide a less discarded water supply device.

  If it is determined in step S3 in FIG. 2 that there is no drain water in the drain tank 16 (No in step S3 in FIG. 2), the control unit 100 does not perform drain water drainage from the drain tank 16. , Only clean up the piping. The cleaning process of the reheating pipe here is the same process as the cleaning process of the reheating pipe with the drain water draining process described above.

  Therefore, even if drain water is not stored in the drain tank 16, when the remaining hot water in the bathtub B is drained, the reheating pipe is washed, so the remaining hot water remaining in the reheating pipe during bathing is also present. It is washed after bathing and can keep the reheating pipe clean. In addition, when the drain water in the drain tank 16 is small, the drain water is not discharged through the recirculation pipe, so that the three-way valve 20 on the appliance side, the water electromagnetic valve 29, Since the operation of the circulation pump 11 and the like can be omitted, it is possible to suppress the wear of the parts that operate in accordance with the drain water discharge process and to extend the life.

  The above-described embodiments show preferred embodiments of the present invention, and the present invention is not limited to these, and various design changes can be made within the scope of the invention.

  For example, in the above-described embodiment, the drain water in the drain tank 16 is discharged on the condition that the drain water is stored in the drain tank 16. When drainage is detected, the drain water can be automatically discharged without determining whether drain water is stored in the drain tank 16 or not. That is, the control part 100 can also be comprised so that it may wash the reheating pipe following the drain water discharge process on condition that the drainage of the hot water in the bathtub B is detected.

  In the above-described embodiment, the case where the water supplied to the inlet pipe 3 is used as clean hot water used for cleaning the reheating pipe is shown. For example, the hot water supplied from the outlet pipe 4 is used. Thus, it is also possible to configure so as to clean the reheating pipe.

  Further, in the above-described embodiment, the determination as to whether or not there is drain water in the drain tank 16 shows the case where it is determined that there is drain water if the water level in the drain tank 16 is equal to or higher than the lower end of the electrode 17b. The water level that serves as a reference for this determination is not limited to being lower than the lower end of the water level electrode 17b as long as it is set in the vicinity of the lowest water level that can be detected by the water level detection means. In short, it is only necessary to be able to determine that the drain tank 16 is not empty or nearly empty, and the water level serving as the determination reference can be appropriately changed.

DESCRIPTION OF SYMBOLS 1 Heat exchanger part 1a Heat exchanger part 1b for hot water supply Heat exchanger part 2 for reheating 2 Burner 3 Intake pipe 4 Outlet pipe 7 Circulation adapter 8 Slow return pipe 9 Slow forward pipe 11 Circulation pump 12 Water flow switch 13 Neutralization 16 Drain tank (drain water storage tank)
17 Water level electrode (water level detection means)
20 Three-way valve 21 on the appliance side Two-way valve 22 Three-way valve 23 on the bathtub side Drain water discharge pipe 24 Drain pipe 27 Drainage detection means 100 Control part B Bathtub

Claims (4)

In the hot water supply apparatus provided with a structure for supplying the drain water generated in the heat exchanger section to the drain water discharge pipe through the reheating pipe while providing the reheating pipe between the bathtub and the bathtub ,
Hot water supply means for supplying clean hot water to the reheating pipe;
Drainage detection means for detecting drainage of hot water in the bathtub;
A control unit,
The controller performs a process of supplying the drain water to the drain water discharge pipe via the reheating pipe on the condition that the drainage of the hot water in the bathtub is detected by the drain detection means. A hot water supply apparatus comprising a control configuration for performing a process of supplying clean hot water to the reheating pipe by the hot water supply means and cleaning the reheating pipe. A drain water storage tank for storing drain water generated in the heat exchanger section;
Water level detecting means for detecting the water level in the drain water storage tank,
In addition to detecting the drainage of hot water in the bathtub by the drainage detection means, the control unit, on the condition that the water level in the drain water storage tank detected by the water level detection means is equal to or higher than a predetermined water level, After performing the process of supplying the drain water to the drain water discharge pipe via the reheating pipe, clean hot water is supplied to the reheating pipe by the hot water supply means. The hot water supply apparatus according to claim 1, further comprising a control configuration that executes a process of cleaning the pipe.   The hot water supply apparatus according to claim 2, wherein the predetermined water level is set in the vicinity of the lowest water level detectable by the water level detection means.   2. The hot water supply means is also used as a pouring means provided for filling or adding hot water to a bathtub and / or a pouring means provided for adding water to a bathtub. The hot water supply apparatus in any one of 3.

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