JP7119961B2 - water heater - Google Patents

Description

This invention relates to a water heater.

Patent Literature 1 discloses a water heater. The water heater includes a sterilization device. The sterilization device sterilizes the bath water based on the bathing pattern. Therefore, bath water can be kept sanitary.

JP-A-11-47012

However, in the hot water heater described in Patent Document 1, the sterilization device may be abused. In this case, the life of the sterilization device may become shorter than the life of the water heater.

The present invention was made to solve the above problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a water heater capable of extending the life of a sterilization device.

A water heater according to the present invention comprises a sensor for detecting the level of bathing water, a sterilization device for sterilizing the bathing water in a bathing water flow path, and learning a bathing pattern from changes in the water level detected by the sensor, Based on the bathing pattern, the cumulative bath water sterilization operation time of the sterilization device within a preset period is estimated, and if the cumulative bath water sterilization operation time exceeds the preset upper limit time, and a control unit that suppresses the operation time of the sterilization device from before the determination so that the operation time of the sterilization device does not exceed the upper limit time.

According to this invention, the life of the sterilization device can be extended.

1 is a configuration diagram of a water heater in Embodiment 1. FIG. FIG. 3 is a circuit configuration diagram of the water heater in the sterilization operation in Embodiment 1; FIG. 5 is a diagram showing the sterilization effect when an ultraviolet LED is used as the ultraviolet irradiation device of the water heater in Embodiment 1; 4 is a time chart of bathing determination by the water heater in Embodiment 1. FIG. 4 is a time chart of an example of bathing pattern learning by the water heater in Embodiment 1. FIG. 4 is a time chart showing an example of control of the sterilization device by the water heater in Embodiment 1. FIG. 4 is a time chart showing an example of control of the sterilization device by the water heater in Embodiment 1. FIG. FIG. 4 is a diagram showing an example of bacteria growth rate of bath water to which the water heater in Embodiment 1 is applied; 4 is a diagram showing an example of control by the water heater in Embodiment 1. FIG. FIG. 4 is a diagram showing the surplus time and cumulative sterilization operation time of the water heater in Embodiment 1;

A mode for carrying out the present invention will be described with reference to the accompanying drawings. In addition, the same code|symbol is attached|subjected to the part which is the same or corresponds in each figure. Redundant description of the relevant part will be simplified or omitted as appropriate.

Embodiment 1.
FIG. 1 is a configuration diagram of a water heater according to Embodiment 1. FIG. The water heater 35 in FIG. 1 is a device that supplies hot water to the bathtub 30 or the like. The water heater 35 includes a tank unit 33 , an HP unit 7 and a remote controller 44 . The tank unit 33 has a hot water storage tank 8 . The hot water storage tank 8 stores hot water. The HP unit 7 is connected to the tank unit 33 via electrical wiring (not shown). Although not shown, the remote control device 44 includes a display section, an operation section, a speaker, a microphone, and the like. For example, the display unit displays information on the state of the water heater 35 . For example, the operation unit is a switch operated by the user. For example, the speaker notifies the user of information by voice, sound, or the like. The remote control device 44 receives an operation to change the setting value and outputs a driving operation command.

The controller 36 is built in the tank unit 33 . Control unit 36 is connected to remote control device 44 so as to be able to communicate with each other. The control unit 36 is electrically connected to various valves, pumps, etc. provided in the tank unit 33 and the HP unit 7 . The control unit 36 controls the operation of various valves, pumps, etc. provided in the tank unit 33 and the HP unit 7 .

The tank unit 33 includes a water inlet 8a, a hot water outlet 8d, a hot water inlet 8e, an intermediate water outlet 8f, and a plurality of stored hot water temperature sensors 41, 42, and 43. A water inlet 8 a is provided at the bottom of the hot water storage tank 8 . The water inlet 8a receives the inflow of water into the hot water storage tank 8 supplied from a water source such as a tap. A hot water outlet 8 d is provided in the upper portion of the hot water storage tank 8 . The hot water outlet 8 d supplies hot water stored inside the hot water storage tank 8 to the outside of the hot water heater 35 . A hot water inlet 8 e is provided in the upper portion of the hot water storage tank 8 . The hot water inlet 8 e receives the inflow of high-temperature hot water from the HP unit 7 into the hot water storage tank 8 . The middle-temperature water outlet 8 f is provided in the center of the hot water storage tank 8 . The intermediate hot water outlet 8f supplies the hot water stored inside the hot water storage tank 8 to the outside of the water heater 35 . A plurality of stored hot water temperature sensors 41, 42, and 43 are mounted on the surface of the hot water storage tank 8 at different heights in the vicinity of the intermediate water outlet 8f and in the vertical direction. The stored hot water temperature sensors 41, 42, 43 detect the temperature of hot water at respective positions.

The tank unit 33 has a three-way valve 11 , a first four-way valve 16 and a second four-way valve 18 . The three-way valve 11 has an a port, a b port, and a c port. The three-way valve 11 is provided so as to be switchable between a channel connecting the a port and the c port and a channel connecting the b port and the c port. Hot water flows in from a port and b port. Hot water flows out from the c port. The first four-way valve 16 has an a port, a b port, a c port, and a d port. The first four-way valve 16 has a flow path connecting the a port and the c port, a flow path connecting the a port and the d port, a flow path connecting the b port and the c port, and a flow path connecting the b port and the d port. It is provided switchably between. Hot water flows in from a port and b port. Hot water flows out from c port and d port. The second four-way valve 18 has an a port, a b port, a c port, and a d port. The second four-way valve 18 is provided so as to be switchable among a channel connecting the a port and the b port, a channel connecting the a port and the c port, and a channel connecting the a port and the d port. Hot water flows in from the a port. Hot water flows out from b port, c port, and d port.

The tank unit 33 includes a water outlet pipe 10, a first water pipe 13a, an HP going pipe 14, an HP return pipe 15, a second water pipe 13b, a first hot water pipe 17a, a third hot water pipe 19a, and a fourth hot water pipe 19b. , a fifth hot water pipe 19c. The water outlet pipe 10 connects the water outlet 8 b and the a port of the three-way valve 11 . The first water supply pipe 13 a connects the c port of the three-way valve 11 and the inlet side of the heat source pump 12 . The HP outgoing pipe 14 connects the outlet side of the heat source pump 12 and the inlet side of the HP unit 7 . The HP return pipe 15 connects the outlet side of the HP unit 7 and the b port of the first four-way valve 16 . The second water supply pipe 13 b branches from between the heat source pump 12 and the inlet side of the HP unit 7 in the HP outgoing pipe 14 and is connected to the a port of the first four-way valve 16 . The first hot water pipe 17 a connects the d port of the first four-way valve 16 and the a port of the second four-way valve 18 . The third hot water pipe 19a connects the b port of the second four-way valve 18 and the hot water inlet 8e. The fourth hot water pipe 19b connects the d port of the second four-way valve 18 and the hot water outlet 8d. The fifth hot water pipe 19c connects the c port of the second four-way valve 18 and the medium temperature water inlet 8g.

The tank unit 33 includes a first water supply pipe 9 a , a pressure reducing valve 31 , a second water supply pipe 9 b , a medium temperature water switching valve 78 , a third water supply pipe 9 c , a fourth water supply pipe 9 d and a medium temperature pipe 79 . One end of the first water supply pipe 9a is connected to a water source such as tap water. The pressure reducing valve 31 is connected to the other end of the first water supply pipe 9a. One end of the second water supply pipe 9b is connected to the pressure reducing valve 31 . The a port of the medium-temperature water switching valve 78 is connected to the other end of the second water supply pipe 9b. One end of the third water supply pipe 9c is connected to the middle of the second water supply pipe 9b. The other end of the third water supply pipe 9c is connected to the water inlet 8a. A water supply line is configured by the first water supply line 9a, the second water supply line 9b, and the third water supply line 9c. One end of the fourth water supply pipe 9 d is connected to the c port of the medium-temperature water switching valve 78 . One end of the medium-temperature pipe 79 is connected to the medium-temperature water outlet 8f. The other end of the medium-temperature pipe 79 is connected to the b port of the medium-temperature water switching valve 78 .

The tank unit 33 includes a bath going pipe 27 , a bath returning pipe 28 , a heat source pump 12 , and a bath heat exchanger 20 . One end of the bath going pipe 27 and one end of the bath returning pipe 28 are connected to the bathtub 30 . The heat source pump 12 is provided on the first water supply pipe 13a. The heat source pump 12 circulates hot water through various pipes inside the tank unit 33 . The bath heat exchanger 20 is connected to the other end of the bath going pipe 27 and the other end of the bath returning pipe 28 . The bath heat exchanger 20 uses high-temperature hot water supplied from the hot water storage tank 8 to heat target water (bath water) on the secondary side, and uses low-temperature water supplied from the lower part of the hot water storage tank 8. Heat is recovered from target water (bath water) on the secondary side for cooling.

The tank unit 33 includes a bath circulation pump 29 , a bath return temperature sensor 38 , a bath going temperature sensor 37 , a water level sensor 46 and a flow switch 47 . For example, the bath circulation pump 29 , the bath return temperature sensor 38 , the water level sensor 46 and the flow switch 47 are provided in the bath return pipe 28 . For example, the bath-going temperature sensor 37 is provided in the middle of the bath-going pipe 27 . Bath circulation pump 29 circulates bath water. Bath return temperature sensor 38 detects the temperature of bath water coming out of bathtub 30 . The bath going temperature sensor 37 detects the temperature of hot water after heat exchange coming out of the bath heat exchanger 20 . The water level sensor 46 detects the level of residual water inside the bathtub 30 . The flow switch 47 detects circulation of water in the bath return pipe 28 .

The tank unit 33 includes a first tank circulation pipe 20a, a third tank circulation pipe 20c, and a second tank circulation pipe 20b. One end of the first tank circulation pipe 20a is connected to the hot water inlet 8e. The other end of the first tank circulation pipe 20a is connected to the primary inlet of the bath heat exchanger 20 . One end of the third tank circulation pipe 20c is connected to the primary outlet of the bath heat exchanger 20 . The other end of the third tank circulation pipe 20 c is connected to the b port of the three-way valve 11 . One end of the second tank circulation pipe 20b is connected to the middle of the third tank circulation pipe 20c. The other end of the second tank circulation pipe 20b is connected in the middle of the intermediate temperature pipe 79 .

The tank unit 33 includes a check valve 50 , a hot water outlet pipe 21 , a hot water mixing valve 22 , a bath mixing valve 23 , a hot water tap 34 , a hot water pipe 24 , a bath pipe 25 and a bath electromagnetic valve 26 . The check valve 50 is provided in the second tank circulation pipe 20b in a direction to block the flow from the middle portion of the hot water storage tank 8 to the lower portion of the hot water storage tank 8. As shown in FIG. One end of the hot water outlet pipe 21 is connected to the confluence point of the hot water outlet 8d. The hot water side of the hot water supply mixing valve 22 is connected to the other end of the hot water lead-out pipe 21 . The water side of the hot water supply mixing valve 22 is connected to the other end of the fourth water supply pipe 9d. The hot water side of the bath mixing valve 23 is connected to the other end of the hot water lead-out pipe 21 . The water side of the bath mixing valve 23 is connected to the other end of the fourth water supply pipe 9d. The hot water tap 34 is connected to a faucet (not shown) such as a shower or a faucet used by the user. One end of the hot water supply pipe 24 is connected to the hot water supply mixing valve 22 . The other end of hot water supply pipe 24 is connected to hot water supply valve 34 . One end of the bath pipe 25 is connected to the bath mixing valve 23 . The bath solenoid valve 26 is connected to the other end of the bath pipe 25 and the bath heat exchanger 20 .

The hot water supply mixing valve 22 adjusts the flow rate ratio between the hot water supplied from the hot water lead-out pipe 21 and the low temperature or medium temperature water supplied from the fourth water supply pipe 9d. As a result, the hot water having the set temperature set by the user with the remote controller 44 is generated. The hot water flows into the hot water supply pipe 24 . The hot water is supplied to a faucet (not shown) such as a shower or a faucet used by the user via the hot water tap 34 .

The bath mixing valve 23 adjusts the flow rate ratio between the high temperature water supplied from the hot water lead-out pipe 21 and the low temperature or medium temperature water supplied from the fourth water supply pipe 9d. As a result, the set temperature and the set amount of hot water set by the user with the remote controller 44 are generated. The hot water flows into the bath pipe 25 . The hot water is supplied to the bathtub 30 via the bath electromagnetic valve 26 , the bath flow rate sensor 45 , the bath going pipe 27 and the bath return pipe 28 . The remote control device 44 is equipped with automatic bath operation. When the automatic bath operation is set, the bath water is heated, cooled, added, or heated as necessary so that the bath water temperature and the amount of hot water in the bathtub are maintained at the temperature and amount set by the remote control device 44 . Sashimizu is done.

The HP unit 7 functions as heating means for heating low-temperature water or the like guided from the hot water storage tank 8 provided in the tank unit 33 . The HP unit 7 configures a heat pump cycle by annularly connecting the compressor 1 , the water-refrigerant heat exchanger 3 , the expansion valve 4 , and the air heat exchanger 6 with the refrigerant circulation pipe 5 . The water-refrigerant heat exchanger 3 exchanges heat between the refrigerant flowing through the refrigerant circulation pipe 5 and the low-temperature water guided from the tank unit 33 . As a configuration of the water-refrigerant heat exchanger 3, heat may be exchanged between the refrigerant flowing through the refrigerant circulation pipe 5 and the low-temperature water directly supplied from a water source such as tap water.

In the water heater 35, hot water heated using the HP unit 7 flows into the hot water storage tank 8 from the hot water inlet 8e. Low-temperature water supplied from a water source such as a tap is adjusted to a preset pressure by a pressure reducing valve 31 from the first water supply pipe 9a, and flows into the hot water storage tank 8 through the third water supply pipe 9c. . As a result, the hot water storage tank 8 stores hot water so that a temperature difference occurs between the upper and lower portions. The controller 36 detects the temperature distribution of the hot water inside the hot water tank 8 based on the detection results of the hot water temperature sensors 41 , 42 and 43 . As a result, the control unit 36 grasps the remaining hot water amount inside the hot water storage tank 8 based on the detection result of the temperature distribution. The control unit 36 controls the start and stop of the heating operation of the hot water in the hot water storage tank 8 by the HP unit 7 based on the remaining hot water amount.

For example, the control unit 36 performs boiling operation by starting the operation of the HP unit 7 . As a result, the low temperature water flowing out from the lower part of the hot water storage tank 8 is led to the HP unit 7 via the HP outgoing pipe 14 . The low-temperature water becomes high-temperature water after being heated in the water-refrigerant heat exchanger 3 . The high-temperature water flows into the inside of the hot water storage tank 8 from the upper portion of the hot water storage tank 8 via the HP return pipe 15 and is stored. By executing the boiling operation, high-temperature water is stored inside the hot water storage tank 8 from the upper layer. The layer of hot water gradually thickens. When the amount of remaining hot water in the hot water storage tank 8 ascertained by the hot water temperature sensors 41, 42, and 43 exceeds a preset amount, the controller 36 stops the boiling operation.

FIG. 2 is a circuit configuration diagram of the hot water supply machine in the sterilization operation according to the first embodiment. During the sterilization operation, when the bath circulation pump 29 starts operating, circulation of the bath water is started. Thereafter, the bath water is sterilized by operating the sterilization device 49 . For example, the sterilization device 49 is an ultraviolet irradiation device, an ozone generator, a heavy metal ion generator, an ultrasonic generator, a fine bubble generator, or the like.

FIG. 3 is a diagram showing the sterilization effect when an ultraviolet LED is used as the ultraviolet irradiation device of the water heater in Embodiment 1. FIG. As shown in FIG. 3, the bath water is disinfected by irradiating the bath water with ultraviolet rays.

FIG. 4 is a time chart of bathing determination by the water heater according to the first embodiment. The control unit 36 determines whether or not the user is taking a bath based on the detection result of the water level inside the bathtub 30 by the water level sensor 46 . The control unit 36 detects a rapid increase or decrease in the water level, and determines bathing when Δt has passed since the rapid decrease in the water level. For example, the control unit 36 determines bathing until 30 minutes have passed since the water level suddenly decreased. The control unit 36 stores the bathing determination result data together with the time data. Δt is set so as to prevent the sterilization device 49 from operating while the user is taking a bath. For example, Δt is set so as to suppress the operation of the sterilization device 49 when the user takes a bath for a short time to wash the body.

The control unit 36 starts the sterilization operation in accordance with the time before the user takes a bath, based on the determination result of whether or not the user takes a bath. After that, the control unit 36 determines that the user is taking a bath when a change in the bathing water level is detected. In this case, the controller 36 stops the sterilization operation.

FIG. 5 is a time chart of an example of bathing pattern learning by the water heater according to the first embodiment. The control unit 36 derives the bathing frequency by accumulating the determination result of whether or not the user takes a bath for each day of the week. The control unit 36 derives the time period when the frequency of bathing is high. The control unit 36 determines that the time period is the time period during which the user takes a bath.

FIGS. 6 and 7 are diagrams showing control examples of the sterilization device by the water heater in the first embodiment. The control unit 36 counts the accumulated bathing water disinfecting operation time from the power supply time to the disinfecting device 49 . The life time of the sterilization device 49 is divided by the product life of the water heater 35, and the judgment period is added to the accumulated bath water sterilization operation time of the sterilization device 49 within the judgment period that is a division of human life patterns. An upper limit time and an arbitrary judgment time less than the upper limit time are set.

For example, if the lifetime of the sterilization device 49 is 11,000 hours, the product lifetime of the water heater 35 is 15 years, and the determination period is one week, the upper limit is 14 hours, which is two hours per day. In this case, the determination time is set to 14 hours or less.

The longer the determination time, the longer the operating time of the sterilization device 49 . In this case, the bath water is always disinfected for a user who has few bathing opportunities. If the determination time is short, the operation time of the sterilization device 49 is shortened. In this case, the life of the sterilization device 49 is relatively extended.

During the sterilization operation, if control such as "activate from one hour before the bathing time" is performed, the control unit 36 integrates the sterilization device 49 within a preset period from the learned bathing pattern. Estimate bath water sterilization operation time. The control unit 36 determines whether or not the operation time of the sterilization device 49 within a preset period reaches the upper limit time at the time when the determination time is reached. The control unit 36 notifies the user via the remote controller 44 when determining that the accumulated bath water disinfecting operation time of the disinfecting device 49 within a preset period has reached the upper limit time. At this time, as shown in FIG. 7, the control unit 36 switches the operation of the sterilization device 49 to intermittent operation. For example, as intermittent operation, the control unit 36 performs bath water sterilization for 30 minutes and stops bath water sterilization for 60 minutes.

FIG. 8 is a diagram showing an example of bacterial growth rate of bath water to which the water heater in Embodiment 1 is applied. FIG. 8 shows the growth rate of bacteria in bath water with a one-pass sterilization rate of 80%, a circulation flow rate of 8 L/min, and a bath water of 200 L. As shown in FIG. 8, when bath water sterilization is performed for 30 minutes and bath water sterilization is stopped for 60 minutes, an increase in bacterial growth rate in bath water is suppressed. In this case, if the accumulated bath water disinfecting operation time per day is two hours, bath water disinfecting can be performed four times for 30 minutes. One 30-minute bath water sterilization suppresses the growth of bacteria in the bath water for 1.5 hours. Therefore, the growth of bacteria in the bathing water is suppressed during the 6-hour refilling time.

FIG. 9 is a diagram showing an example of control by the water heater according to Embodiment 1. FIG. When the control unit 36 estimates that the cumulative bath water disinfecting operation time within a preset period has reached the upper limit time, it causes the remote controller 44 to display guidance. After that, the control unit 36 switches the sterilization device 49 to intermittent operation.

FIG. 10 is a diagram showing the surplus time and cumulative sterilization operation time of the water heater in the first embodiment.

The control unit 36 determines that the accumulated bath water sterilization operation time within the preset period did not reach the upper limit time in the past, and the cumulative bath water sterilization operation time within the preset period is the upper limit time. is estimated to be reached, the surplus time, which is the difference between the upper limit time and the accumulated bathing water sterilization operation time within a period set in advance in the past, is added to the current upper limit time. At this time, the control unit 36 causes the remote control device 44 to display guidance to confirm with the user whether or not there is a switch to intermittent operation.

According to the first embodiment described above, the control unit 36 operates the sterilization device 49 so that the operating time of the sterilization device 49 within a preset period does not exceed the upper limit time. Therefore, the life of the sterilization device 49 can be extended.

In addition, if the control unit 36 estimates that the accumulated bath water disinfecting operation time of the disinfecting device 49 within the preset period at the time when the determination time is reached reaches the upper limit time, then within the preset period The sterilization device 49 is operated so that the operating time of the sterilization device 49 does not exceed the upper limit time. Therefore, the life of the sterilization device 49 can be extended more reliably.

Specifically, when the control unit 36 estimates that the accumulated bath water sterilization operation time of the sterilization device 49 within a preset period reaches the upper limit time at the time when the determination time is reached, the sterilization device 49 is switched to intermittent operation. Therefore, the life of the sterilization device 49 can be extended more reliably with simple control.

In addition, the control unit 36 determines that the accumulated bath water sterilization operation time of the sterilization device 49 within the preset period in the past did not reach the upper limit time, and the sterilization device 49 within the preset period at present. When it is estimated that the accumulated bath water disinfection operation time of 49 reaches the upper limit time, the surplus time that is the difference between the upper limit time and the accumulated bath water disinfection operation time within a period set in advance in the past is the current surplus time. Add to the upper limit time. Therefore, even if the frequency of use of the sterilization device 49 varies depending on the preset period, the bath water can be kept sanitary while ensuring the long life of the sterilization device 49 .

Note that the control unit 36 delays the timing of switching the operation of the sterilization device 49 to the intermittent operation by the increase in the surplus time. Therefore, it is possible to maintain the bath water more hygienically and reliably while ensuring the long life of the sterilization device 49 .

Note that the control unit 36 may select the determination time from among a plurality of candidates. For example, the determination time may be selected from among a plurality of candidates based on the operation of the remote control device 44 . In this case, the sterilization device 49 can be appropriately used according to the user's bathing pattern.

Further, when the control unit 36 estimates that the accumulated bath water disinfecting operation time of the disinfecting device 49 within a preset period reaches the upper limit time, it causes the remote control device 44 to notify guidance. Therefore, it is possible to inform the user that the sterilization device 49 is used frequently.

When the total operation time of the sterilization device 49 reaches a time obtained by subtracting a preset time from the operating life time of the sterilization device 49, the control unit 36 intermittently operates the sterilization device 49. , and the remote control device 44 may notify that the sterilization device 49 is nearing its end of life and needs to be dealt with. In this case, it is possible to prevent the bath water from being sanitary due to the lifetime of the sterilization device 49 .

Note that the preset time may be a grace period required by the user to replace the sterilization device that has reached the end of its life. For example, the preset period may be a period from when a repair is requested to a store or service center until the repair is completed. For example, the preset period may be appropriately set to one month, two weeks, or the like according to the bathing pattern.

Further, the controller 36 may cause the remote control device 44 to always inform the operating state of the sterilization device 49 . Therefore, it is possible to inform the user whether the sterilization device 49 is operating continuously or intermittently.

REFERENCE SIGNS LIST 1 compressor 3 water-refrigerant heat exchanger 4 expansion valve 5 refrigerant circulation pipe 6 air heat exchanger 7 HP unit 8 hot water storage tank 8a water inlet 8b water outlet 8c water inlet 8d hot water outlet 8e hot water inlet 8f intermediate hot water Outlet 8g Mid-temperature water inlet 9a First water supply pipe 9b Second water supply pipe 9c Third water supply pipe 9d Fourth water supply pipe 10 Water outlet pipe 11 Three-way valve 12 Heat source pump 13a First water supply pipe 13b Second water supply pipe 14 HP Outgoing pipe 15 HP return pipe 16 First four-way valve 17a First hot water pipe 17b Second hot water pipe 18 Second four-way valve 19a Third hot water pipe 19b Fourth hot water pipe 19c Fifth hot water pipe 20 Bath heat exchanger 20a First Tank circulation pipe 20b Second tank circulation pipe 20c Third tank circulation pipe 21 Hot water lead-out pipe 22 Mixing valve for hot water supply 23 Mixing valve for bath 24 Hot water supply pipe 25 Bath pipe 26 Solenoid valve for bath 27 To/from bath pipe 28 Return to bath pipe 29 Bath Circulation pump 30 Bathtub 31 Pressure reducing valve 33 Tank unit 34 Hot water tap 35 Hot water heater 36 Control unit 37 Bath going temperature sensor 38 Bath returning temperature sensor 41 Hot water storage temperature sensor 42 Hot water storage temperature sensor 43 Hot water storage temperature sensor 44 Remote controller 45 Bath flow rate sensor 46 Water level sensor 47 Flow switch 49 Sterilization device 50 Check valve 78 Medium temperature water switching valve 79 Medium temperature pipe

Claims (9)

a sensor that detects the water level of the bath water;
a sterilization device for sterilizing the bath water in the flow path of the bath water;
A bathing pattern is learned from changes in the water level detected by the sensor, an accumulated bath water sterilization operation time of the sterilization device within a preset period is estimated from the bathing pattern, and the estimated total bath water sterilization is performed. When it is determined that the sterilization operation time exceeds the preset upper limit time, the operation time of the sterilization device is reduced so that the operation time of the sterilization device within the preset period does not exceed the upper limit time. a control unit that suppresses more than before the judgment;
water heater. The control unit sets the upper limit time and a judgment time shorter than the upper limit time for the operation time of the sterilization device within a preset period, and the judgment time is reached from the learned bathing pattern. If it is estimated that the integrated bath water sterilization operation time of the sterilization device within the preset period at the time of the The water heater according to claim 1, wherein the sterilization device is operated so as not to exceed the upper limit time. When the control unit estimates that the accumulated bath water sterilization operation time of the sterilization device within a preset period at the time when the determination time is reached from the learned bathing pattern, The water heater according to claim 2, wherein the operation of the sterilization device is switched to intermittent operation. The control unit determines that the accumulated bath water disinfection operation time of the disinfection device within a preset period in the past did not reach the upper limit time, and the disinfection device is currently within a preset period. If it is estimated that the accumulated bath water disinfecting operation time reaches the upper limit time, the surplus time that is the difference between the upper limit time and the accumulated bath water disinfecting operation time within a preset period in the past is now 4. The water heater according to claim 3, which is added to the upper limit time of. 5. The water heater according to claim 4, wherein the control unit delays the timing of switching the operation of the sterilization device to the intermittent operation by the amount of the surplus time. The water heater according to any one of claims 2 to 5, wherein the control unit is provided so that the determination time is selected from a plurality of candidates. When the control unit estimates that the accumulated bath water disinfection operation time of the disinfection device within a preset period reaches the upper limit time, the control unit causes the remote control device to notify the guidance. The water heater according to any one of 1. When the total operating time of the sterilization device reaches the operating life time of the sterilization device minus the grace period required for replacement of the sterilization device, the control unit operates the sterilization device. 7. The water heater according to any one of claims 2 to 6, wherein the operation is switched to intermittent operation, and the remote control device is notified that the sterilization device is nearing the end of its life. The water heater according to any one of claims 2 to 6, wherein the control unit causes a remote controller to notify the operating state of the sterilization device.

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