JP7501407B2 - Water heater - Google Patents

Description

This disclosure relates to a water heater. More specifically, it relates to a water heater with a bathtub cleaning function.

Conventionally, a storage-type water heater with a bathtub cleaning function has been proposed, which adds detergent to clean the inside of the bathtub when the bathwater is drained. In this regard, for example, Patent Document 1 describes the use of multiple detergents depending on the cleaning mode when cleaning the bathtub with a storage-type water heater.

Japanese Patent Application Laid-Open No. 11-206602

If the bathtub drain is clogged with hair or other foreign matter, the bathtub water will drain slower than expected. This can result in situations that reduce the convenience of bathtub cleaning, such as not being able to clean the bathtub effectively or not finishing the bathtub cleaning at the scheduled time.

To solve the problems described above, the present disclosure provides an improved water heater that can suppress a decrease in the convenience of cleaning the bathtub even when the drainage speed is slowing.

The water heater of the present disclosure includes a detection means for detecting the drainage speed of bath water from the bath, a first storage unit for storing a first detergent, a second storage unit for storing a second detergent having a different cleaning effect from the first detergent, a first detergent flow path for supplying the first detergent from the first storage unit to the bath, a second detergent flow path for supplying the second detergent from the second storage unit to the bath, a rinse water flow path for supplying water as rinse water to the bath, a discharge unit disposed in the bath and connected to the first detergent flow path, the second detergent flow path, and the rinse water flow path, capable of discharging the first detergent, the second detergent, and the rinse water into the bath, and a control unit for controlling the supply of the first detergent, the second detergent, and the rinse water to the bath when the bath water is drained to perform bath water cleaning. The control unit is configured to perform bath water cleaning in a first mode in which the first detergent is poured into the bath and rinse water is supplied when the drainage speed is faster than a judgment value, and to perform bath water cleaning in a second mode in which the first detergent is poured into the bath and the second detergent is poured into the bath and rinse water is supplied when the drainage speed is equal to or less than the judgment value.

According to the water heater disclosed herein, the cleaning mode is selected according to the drainage speed, making it possible to prevent a decrease in the convenience of the bathtub cleaning function due to a decrease in the drainage speed.

1 is a schematic diagram showing the configuration of a bath hot water supply system according to a first embodiment of the present disclosure. FIG. 4 is a flowchart showing a control operation of bathtub cleaning according to the first embodiment of the present disclosure. 4 is a timing chart showing a bathtub cleaning operation in the first embodiment of the present disclosure. FIG. 11 is a diagram showing an overview of calculation of a waiting time according to a second embodiment of the present disclosure.

The following describes the embodiments with reference to the drawings. Elements common to each figure are given the same reference numerals, and duplicate descriptions are simplified or omitted. The present disclosure may include any combination of possible configurations among those described in each of the following embodiments. In addition, when "water" or "hot water" is written in the following embodiments, it may include liquid water of any temperature, from cold water to boiling water.

Embodiment 1.
Fig. 1 is a schematic diagram showing the configuration of a bath hot water supply system according to embodiment 1. The bath hot water supply system 1 of this embodiment includes a water heater 3, a flow path system 4, a control unit 12, and a remote control device 13. A bathroom 100 is equipped with a bathtub 2, and the water heater 3 is connected to the bathtub 2 via the flow path system 4.

There is no limitation on the type of water heater 3, as long as it can supply hot water at an appropriate temperature to the bathtub 2. For example, the water heater 3 may be a storage type water heater equipped with a hot water storage tank, or an instantaneous water heater.

The flow path system 4 includes a circulation circuit 5 and a hot water supply flow path 22. The hot water supply flow path 22 connects the hot water heater 3 and the circulation circuit 5. A bath solenoid valve 21 is installed in the hot water supply flow path 22. The hot water supply flow path 22 may also be configured to include a mixer that adjusts the hot water temperature by mixing low-temperature water supplied from the water supply pipe.

The circulation circuit 5 includes a first circulation flow path 6, a heat exchanger 9, a second circulation flow path 7, and a bathtub adapter 10. The bathtub adapter 10 is attached to the bathtub 2. A water outlet 11 for discharging water into the bathtub 2 is connected to the bathtub adapter 10. The first circulation flow path 6 and the second circulation flow path 7 each connect the secondary flow path of the heat exchanger 9 and the bathtub adapter 10. A first solenoid valve 20, which will be described later, is installed in the first circulation flow path 6. A circulation pump 8 is installed in the middle of the second circulation flow path 7. The heat exchanger 9 is a heating means that exchanges heat between the heat source water flowing through the primary flow path and the water to be heated (i.e., bathtub water) flowing through the secondary flow path. However, the heat exchanger 9 is not limited to this, and may be any means that has the function of heating the bathtub water. For example, instead of the heat exchanger 9, a heating means that heats the bathtub water with an electric heater may be used, or a heating means that heats the bathtub water with the combustion heat of fuel may be used. In addition, a water level sensor 17 is installed in the second circulation flow path 7. The water level sensor 17 is a sensor that detects the water pressure in the second circulation flow path 7.

The bath hot water supply system 1 further includes a storage container 16 for storing detergent. The storage container 16 can store multiple detergents separately. In this embodiment, the storage container 16 has a first storage section 16a and a second storage section 16b. The first storage section 16a stores a first detergent A, and the second storage section 16b stores a second detergent B. The second detergent B is a detergent with a different cleaning effect from the first detergent A. In this embodiment, the second detergent B is a detergent with a higher cleaning effect than the first detergent A. The second detergent B can dissolve and remove foreign matter such as hair that accumulates in the drain. The storage container 16 may have three or more storage sections and may be configured to store three or more types of detergent. The storage container 16 is provided with a water level sensor 25 for detecting the water level of the remaining amount of detergent in each of the first storage section 16a and the second storage section 16b.

The bathtub 2 is fitted with a detergent outlet 18, which is an outlet that sprays detergent into the bathtub 2. The storage container 16 and the detergent outlet 18 are connected by a detergent supply path. The detergent supply path has a first flow path 23a, a second flow path 23b, and a common flow path 23c. A second solenoid valve 19 is provided at the connection between the first flow path 23a, the second flow path 23b, and the common flow path 23c. The second solenoid valve 19 has two inlets a, b, and one outlet c. The first flow path 23a connects the first storage section 16a to the inlet a, the second flow path 23b connects the second storage section 16b to the inlet b, and the common flow path 23c connects the detergent outlet 18 to the outlet c.

The second solenoid valve 19 is a switching valve that can switch the flow path between a first detergent flow path to which the first detergent A of the storage container 16 is supplied and a second detergent flow path to which the second detergent B is supplied, by opening and closing the inlets a, b and outlet c. Specifically, by opening the inlet a and outlet c of the second solenoid valve 19 and closing the inlet b, the flow path is switched to the first detergent flow path in which the first storage section 16a and the detergent discharge port 18 are connected. On the other hand, by opening the inlet b and outlet c of the second solenoid valve 19 and closing the inlet a, the flow path is switched to the second detergent flow path in which the second storage section 16b and the detergent discharge port 18 are connected.

A first solenoid valve 20 is provided in the middle of the first circulation flow path 6. The first circulation flow path 6 is connected to the inlet a of the first solenoid valve 20 and one of the two outlets, outlet b. One end of a branch flow path 24 is connected to the other of the two outlets, outlet c, of the first solenoid valve 20. The other end of the branch flow path 24 is connected to a common flow path 23c. When the outlet b of the first solenoid valve 20 is closed and the inlet a and outlet c are open, the water supplied from the water heater 3 is switched to the hot water supply flow path 22, the first circulation flow path 6, and the rinsing water flow path that is supplied to the detergent discharge port 18 via the branch flow path 24.

The remote control device 13 is an example of a user interface. The remote control device 13 is provided with an operation unit 14 and a display 15 as a display unit. The remote control device 13 may be provided with a touch screen having the functions of both the display unit and the operation unit. The operation unit 14 is an operation means that accepts operation input of commands related to the operation of the bath hot water supply system 1. A person such as a user can remotely operate the operation of the bath hot water supply system 1 and perform various settings by operating the operation unit 14. The operation unit 14 may be provided with various buttons or keys. The display 15 functions as a notification means and can notify a person such as a user of information regarding the operating state of the bath hot water supply system 1. The remote control device 13 may be equipped with a speaker, a microphone, etc. As a modified example, for example, the remote control device 13 may be provided with another notification unit such as a voice guidance device instead of the display 15 as a display unit. In addition, a mobile information terminal such as a smartphone may be configured to have a function as a user interface like the remote control device 13. A configuration having multiple remote control devices 13 may be used.

The control unit 12 has at least one memory and at least one processor. The control unit 12 is connected to the bath hot water supply system 1 by wire or wirelessly, and controls the operation of the bath hot water supply system 1. Note that the control unit 12 is not limited to being composed of a single control unit, and may be configured to have multiple control units working together to control. Also, here, the control unit 12 is assumed to be mounted on the water heater 3, but there is no limitation on where the control unit 12 is installed, and for example, the control unit 12 may be mounted on the remote control device 13.

In addition to the water level sensor 17 and water level sensor 25 described above, various sensors installed in the bath water supply system 1 are connected to the control unit 12. For example, the control unit 12 can detect the water level of the bath water remaining in the bathtub 2 based on the data output by the water level sensor 17. The control unit 12 detects the completion of draining of the bath water when the water level sensor 17 can no longer detect the water level of the bath water. The control unit 12 also functions as a detection means that acquires water level data of the bathtub 2 by the water level sensor 17 during draining, and detects the draining speed of the bath water based on this data. Furthermore, the control unit 12 can detect that the materials of the first detergent A or the second detergent B have fallen below their respective reference amounts based on the output of the water level sensor 25 installed in the storage container 16.

The control unit 12 and the remote control device 13 are connected so that they can communicate with each other. Information such as user commands and setting values input from the operation unit 14 of the remote control device 13 is transmitted to the control unit 12. The control unit 12 can also operate the display 15 to display information related to the operating status of the bath hot water supply system.

The control unit 12 is electrically connected to various valves, pumps, etc. equipped in the bath hot water supply system 1 and controls their operation. For example, when filling the bathtub 2 with hot water, the control unit 12 opens the bath solenoid valve 21 and operates the hot water supply pump (not shown). As a result, hot water supplied from the water heater 3 is sent through the hot water supply flow path 22 and the circulation circuit 5, and is injected into the bathtub 2 from the bathtub adapter 10. When reheating bath water, the control unit 12 operates the circulation pump 8, extracts bath water from the bathtub 2 and circulates it in the circulation circuit 5. At this time, the circulation circuit (not shown) supplies high-temperature water from the water heater 3 to the primary flow path of the heat exchange unit 9. As a result, the bath water flowing through the secondary flow path of the heat exchange unit 9 is heated and returned to the bathtub 2.

In addition, in this embodiment, the bath hot water supply system 1 has a bathtub cleaning function that automatically cleans the inside of the bathtub 2 when the bathtub water is drained. The bathtub cleaning function is realized by the control unit 12 controlling the bathtub cleaning. The bathtub cleaning function in this embodiment has two cleaning modes, a first mode and a second mode. The first mode is a mode in which only the entire surface of the bathtub 2 is cleaned with the first detergent A. The second mode is a mode in which the entire surface of the bathtub 2 is cleaned with the first detergent A and cleaned to remove blockages near the drain with the second detergent B.

Figure 2 is a flow chart for explaining the control operation of bathtub cleaning by the control unit 12. The control operation of bathtub cleaning will be explained below with reference to Figures 2 and 3. As shown in Figure 2, in the control of bathtub cleaning, first in step S1, it is determined whether or not draining of bathtub water has started. The start of draining can be detected by the output of the water level sensor 17. Alternatively, if the operation of the drain plug of the drain outlet 26 provided at the bottom of the bathtub 2 can be detected, the start of draining of bathtub water may be detected by the drain plug being changed from a closed state to an open state. If it is not determined in step S1 that the start of draining has been detected, the current process ends.

On the other hand, if it is determined in step S1 that draining of bath water has started, the process proceeds to step S2. In step S2, the water level sensor 17 monitors the change in the water level in the bathtub 2, and obtains the water level h0 at the start of draining and the water level h2 when a reference time t1 has elapsed since draining started. Here, the reference time t1 is a preset value, and is, for example, about 10 seconds.

Next, in step S3, the amount of change Δv in the drainage speed is calculated. As a premise, the control unit 12 acquires and stores the change in the water level of the bathtub 2 when the bathtub 2 is drained for the first time after installation as the initial drainage data x0. The amount of change Δv in the drainage speed is calculated according to the following formula.

In the above formula, the water level h1 is the water level after the reference time t1 has elapsed since the water level h0 (i.e., the water level at the start of the drainage to be judged this time) was reached in the initial drainage data x0. In other words, the change in the drainage speed Δv is a value that indicates the change in the drainage speed to be judged this time relative to the drainage speed when the bathtub 2 was first installed.

Next, in step S4, it is determined whether the change in the drainage speed Δv is smaller than a judgment value. The judgment value is a value that is preset as a threshold value for determining whether the drain outlet 26 is clogged and is stored in the control unit 12. If the calculated change in the drainage speed Δv is smaller than the judgment value, it can be determined that the drainage speed has not changed significantly since the bathtub 2 was first installed, and that the drain outlet 26 is not clogged. Therefore, in this case, the process proceeds to step S10, and the first mode is selected as the cleaning mode.

On the other hand, if the change in the drainage speed Δv is equal to or greater than the judgment value, the drainage speed has dropped significantly compared to when the bathtub 2 was installed, and it is expected that the drain outlet 26 is clogged. Therefore, in this case, the process proceeds to step S20, and the second mode is selected as the cleaning mode.

Regardless of whether the first or second mode is selected, the next step S11 or S21 is to add the first detergent A. Here, the inlet a and outlet c of the second solenoid valve 19 are opened, and the detergent supply path is switched to the first detergent flow path. When the water level in the bathtub 2 drops below the detergent outlet 18, the first detergent flow path becomes high pressure, and the first detergent A is added to the bathtub 2 from the detergent outlet 18. The first detergent A added to the bathtub mixes with the bath water, and the entire surface of the bathtub 2 is cleaned while it is being drained. After a preset amount of first detergent A has been added, the first detergent flow path is closed.

After the first detergent A is dispensed in step S11, in the first mode, the process proceeds to step S12, where it is determined whether a first waiting time ts1 has elapsed since the water level sensor 17 entered a state in which the water level cannot be detected. Here, the water level cannot be detected when the water level is lower than the bathtub adapter 10, and when the first waiting time ts1 has elapsed, the bath water is considered to have been completely drained. The first waiting time ts1 is a preset time, and is, for example, approximately 30 seconds. The user can set the first waiting time ts1 from the operation unit 14 of the remote control device 13.

If it is determined in step S12 that the first waiting time ts1 has not elapsed, the process returns to step S12, and the determination process in step S12 is repeated at regular calculation intervals. If it is determined in step S12 that the first waiting time ts1 has elapsed, the process proceeds to step S30, and rinsing water is supplied. When rinsing water is supplied, the bath solenoid valve 21 is opened, and the inlet a and outlet c of the first solenoid valve 20 are opened. As a result, hot water supplied by the water heater 3 is forcefully sprayed from the detergent outlet 18 through the branch flow path 24 and the common flow path 23c into the bathtub 2, and discharged from the drain 26. As a result, detergent components adhering to the common flow path 23c, the detergent outlet 18, the bathtub 2, and the drain are removed by the rinsing water. Then, the supply of rinsing water is terminated in step S31, and the current process is terminated.

On the other hand, in the second mode, after the first detergent A is dispensed in step S21, the process proceeds to step S22, where it is determined whether or not the water level cannot be detected. If it is not determined in step S21 that the water level cannot be detected, the process returns to step S22, and the determination process of step S22 is repeated at regular calculation intervals.

After that, if it is determined in step S22 that the water level cannot be detected, the process proceeds to step S23, where the second detergent B is poured in. When pouring in the second detergent B, the inlet b and outlet c of the second solenoid valve 19 are opened, and the second storage section 16b and the detergent outlet 18 are connected by the second detergent flow path. As a result, the second detergent B is poured in from the detergent outlet 18 and flows along the inner wall surface of the bathtub 2 to the vicinity of the drain 26. After a preset amount of the second detergent B has been poured in, the second detergent flow path is closed. The second detergent B is a detergent that is highly effective at dissolving foreign matter that has clogged the drain 26, and pouring in the second detergent B clears the clog near the drain 26.

Next, the process proceeds to step S24, where it is determined whether or not the second waiting time ts2 has elapsed since the water level detection became impossible. The second waiting time ts2 is a preset time that is longer than the first waiting time ts1. As an example, the second waiting time ts2 is about 60 seconds. The user can also set the second waiting time ts2 from the operation unit 14 of the remote control device 13.

If it is determined in step S24 that the second waiting time ts2 has not elapsed since the water level cannot be detected, the process returns to step S24, and the determination process of step S24 is repeated at regular calculation intervals. After that, if it is determined in step S24 that the second waiting time ts2 has elapsed, the process proceeds to step S30, and rinsing is performed in the same manner as in the first mode.

Figure 3 is a timing chart showing the relationship between the change in the bathtub water level and the cleaning operation in each of the first and second modes. Figure 3 illustrates the initial drainage data x0 and drainage data x1 as the data of the controlled object when the change in the drainage speed Δv becomes greater than the judgment value. In the example of Figure 3, the water level at the start of drainage of the controlled object is set to water level h0, and for the initial drainage data x0, only the data after the water level h0 at the start of drainage of the controlled object is extracted and shown, and the water level at the start of drainage is set to the same water level h0.

The bathtub cleaning operation in the first mode will be explained using the initial drainage data x0 in Figure 3. When water is drained at a drainage speed close to the initial drainage data x0, i.e., when the change in the drainage speed Δv is smaller than the judgment value, the first mode is selected. In the first mode, the first detergent A is added during drainage. Rinsing is then performed at time T11, which is the first standby time ts1 that has elapsed since time T10, when the water level became zero (i.e., the water level cannot be detected).

In the example of drainage data x1 in FIG. 3, the difference Δh (=h2-h1) between the water level h2 at time T1 after the reference time t1 has elapsed and the water level h1 of the initial drainage data is large, and the change in the drainage speed Δv (=Δh/t1) is larger than the judgment value. In this case, the second mode is selected. Similarly, in the second mode, the first detergent A is added during drainage. In the second mode, the second detergent B is added at time T20 when the water level becomes zero. Then, rinsing is performed at time T21, which is the second standby time ts2 after time T20.

As described above, according to the bath hot water supply system of this embodiment, the cleaning mode is selected according to the drainage speed. As a result, when the drainage speed is fast and the drain outlet 26 is not clogged, it is possible to only clean the surface of the bathtub 2, and bathtub cleaning can be completed early. On the other hand, when the drainage speed is slow and clogging of the drain outlet 26 is expected, the second detergent B is added when drainage is completed. This makes it possible to effectively remove foreign matter that has accumulated in the drain outlet 26. In this way, according to the bath hot water supply system of this embodiment, cleaning can be performed using an appropriate detergent at an appropriate time according to the drainage speed, improving the convenience of bathtub cleaning.

In this embodiment, the cleaning mode is determined by calculating the change in drainage speed Δv and comparing it with the judgment value. However, the parameter for determining the cleaning mode is not limited to the change in drainage speed Δv, and other parameters may be used as long as they indicate a change according to the drainage speed of the bathtub water. The second mode may be set when the drainage speed calculated from the water level h0 at the start of drainage and the water level h2 after the reference time t1 has elapsed is smaller than a predetermined judgment speed. Here, the predetermined judgment speed can be calculated, for example, by subtracting the allowable decrease in the drainage speed from the drainage speed calculated based on the initial drainage data x0. In the following description, parameters for determining the cleaning mode, including the drainage speed and the change in drainage speed Δv, are collectively referred to as "speed parameters".

Regardless of which speed parameter is used, by determining the value that serves as the judgment standard based on the value of the initial drainage data that corresponds to that speed parameter, it is possible to accommodate special drainage patterns due to the shape of the bathtub 2 and environmental conditions related to drainage. Note that the initial drainage data is not limited to only the first drainage data after the bathtub is installed, and average data calculated by learning the water level data during the first multiple drainages after the bathtub 2 is installed may also be used as the initial drainage data. In addition, the judgment value that serves as the judgment standard does not have to be a value determined according to the initial drainage data. For example, the judgment value for the drainage speed may be preset and stored in the control unit 12.

The judgment value for the speed parameter may be configured so that the user can set or change it from the operation unit 14 of the remote control device 13. This allows the user to set the judgment value suitable for the drainage pattern.

In this embodiment, the speed parameter is detected based on the water level data detected by the water level sensor. However, if the bathtub 2 has a stepped shape, or if the diameter of the bathtub 2 varies depending on the location, even if the drainage speed is constant, the water level drop speed will vary depending on the diameter of the bathtub. In this case, there is a risk that the calculated speed parameter will not correspond to the actual drainage speed. In this regard, in this embodiment, the reference range, which is the range of water level data used to obtain the speed parameter, is limited to the period from the start of drainage to the reference time t1. This makes it possible to reduce the influence of the bathtub shape and obtain a speed parameter that corresponds to the actual drainage speed. However, the calculation of the speed parameter is not limited to the case where it is based on the amount of water level drop during the reference time t1. For example, the reference range of water level data used to calculate the speed parameter may be limited by the height of the bathtub 2, and the speed parameter may be calculated.

In addition, in this embodiment, in the second mode, when completion of draining is detected, the second detergent B is immediately dispensed. This makes it possible to reduce the time required for cleaning the bathtub while preventing the second detergent B from being discharged together with the bathtub water. However, the timing for dispensing the second detergent B is not limited to this, and for example, the second detergent B may be dispensed a certain amount of time after completion of draining. This makes it possible to dispense the second detergent B after the bathtub water remaining in the drain outlet 26 has been reliably drained, and prevents the second detergent B before cleaning from flowing out together with the bathtub water. The second detergent B may also be dispensed before completion of draining. This makes it possible to effectively reduce the time required for cleaning the bathtub.

In addition, in this embodiment, a case has been described in which the first waiting time ts1 is set shorter than the second waiting time ts2. This shortens the time required for cleaning the bathtub in the first mode, while ensuring sufficient cleaning effect with the second detergent B in the second mode. However, for example, the first waiting time ts1 and the second waiting time ts2 may be set to the same time. Alternatively, the first waiting time ts1 and the second waiting time ts2 may be configured to be set by the user via the operation unit 14 of the remote control device 13. This can further improve the convenience of the bathtub cleaning function.

The control unit 12 may also be configured to display guidance on the display 15 to notify the user when the drainage speed reaches a level at which the second mode is activated. This notifies the user that the drainage speed is decreasing, and that the drain outlet 26 may be clogged.

Alternatively, the control unit 12 may be configured to display guidance on the display 15 to warn the user when the number of consecutive bathtub cleanings performed in the second mode exceeds a reference number. This makes it possible to warn the user of a slowdown in the drainage speed and the possibility of clogging of the drain outlet 26.

The control unit 12 may also be configured to notify the user that the remaining amount of the first detergent A or the second detergent B is low. Specifically, the control unit 12 detects the remaining amount of each of the first detergent A and the second detergent B using the water level sensor 25, and displays guidance on the display 15 when the remaining amount of the first detergent A is less than the first reference amount, or when the remaining amount of the second detergent B is less than the second reference amount. This notifies the user that the remaining amount of the first detergent A or the second detergent B is low, and prompts the user to add more detergent. In this configuration, the first reference amount and the second reference amount for determining whether or not a notification is required may be different amounts. Since the first detergent A and the second detergent B are different detergents, it is considered that the amount used in one use is different. Even in such a case, by setting a reference amount for each detergent, a notification can be performed at an optimal timing for each detergent.

The cleaning mode for cleaning the bathtub may also be configured so that the user can specify it by inputting an operation from the operation unit 14. In this case, the control unit 12 does not determine the cleaning mode based on the speed parameter, but cleans the bathtub in the cleaning mode specified by the user. This makes it possible to meet the needs of the user, for example, by selecting the second mode at will when the user wants to thoroughly clean the drain 26, thereby improving the convenience of the bath hot water system.

The second mode may also be configured to supply rinsing water after pouring the first detergent A into the tub 2 and before pouring detergent B. By rinsing after pouring the first detergent A, the first detergent A adhering to the surface of the dirt can be washed away. By then pouring the second detergent B, the second detergent B can be reliably delivered to the exposed dirt, and a high cleaning effect can be achieved by the second detergent B. In addition, even if a detergent is not suitable for mixing with the first detergent A, it can be used as the second detergent B, so the user can freely select a detergent with a higher cleaning effect.

Embodiment 2.
The bathtub system of the second embodiment has the same configuration as the bathtub system of the first embodiment, except that the control unit 12 determines the waiting time from the completion of drainage to the start of supplying rinsing water in accordance with a speed parameter. Fig. 4 is a diagram for explaining the outline of the determination of the waiting time. In Fig. 4, the water level at the start of drainage is shown as the same water level h0 for the sake of simplicity of explanation, but the water level at the start of drainage is not limited to being the same. The explanation will be given using the drainage speed as the speed parameter that determines the waiting time.

As shown in FIG. 4, the control unit 12 sets the waiting time ts from the completion of drainage to the supply of rinsing water to be shorter when the bath water drainage speed calculated based on the water level data detected by the water level sensor 17 is fast than when the drainage speed is slow.

Specifically, a drainage speed v0 (=(h0-h01)/t1) during the reference time t1 is calculated from the water level h0 at the start of drainage of the initial drainage data x0, which is the judgment standard, and the water level h1 after the reference time t1 has elapsed. Similarly, for drainage data xi to be judged, a drainage speed vi (=(h0-hi)/t1) during the reference time t1 is calculated from the water level h0 at the start of drainage and the water level hi after the reference time t1 has elapsed. Note that the "i" attached to xi, vi, hi, and tsi is a natural number indicating the number of the drainage data. The waiting time tsi from the completion of drainage to the start of rinsing is calculated according to the following formula.

As a result, as shown in FIG. 4, when comparing drainage data x1 and x2, the waiting time ts1 from the completion of drainage to the start of rinsing when the drainage speed is fast (drainage data x1) is shorter than the waiting time ts2 when the drainage speed is slow (drainage data x2).

As described above, by configuring the waiting time before rinsing begins to be set according to the drainage speed, when the drainage speed is fast and clogging is rare, there is no need to ensure a longer waiting time than necessary until the drainage is completely completed. This makes it possible to reduce the time required to clean the bathtub. Also, when the drainage speed is slow, a longer waiting time is ensured, which prevents rinse water from being supplied and detergent from being washed away before drainage is completely completed.

The waiting time tsi is not limited to being calculated using the above formula, but may be set according to the speed parameter. The relationship between the waiting time tsi and the speed parameter is not limited to being specified and calculated using a function. For example, the waiting time tsi may be set to be gradually longer, such as by setting multiple ranges for the value of the speed parameter and setting the waiting time tsi for each range.

1 Bath hot water supply system, 2 Bathtub, 3 Water heater, 4 Flow path system, 5 Circulation circuit, 6 First circulation flow path, 7 Second circulation flow path, 8 Circulation pump, 9 Heat exchanger, 10 Bathtub adapter, 11 Water outlet, 12 Control unit, 13 Remote control device, 14 Operation unit, 15 Display, 16 Storage container, 16a First storage unit, 16b Second storage unit, 17 Water level sensor, 18 Detergent outlet, 18 Bathtub adapter, 18 Outlet, 18 Detergent outlet, 19 Second solenoid valve, 20 First solenoid valve, 21 Bath solenoid valve, 22 Hot water supply flow path, 23a First flow path, 23b Second flow path, 23c Common flow path, 24 Branch flow path, 25 Water level sensor, 26 Drain, 100 Bathroom

Claims (12)

A detection means for detecting a drainage speed of the bathtub water;
a first storage section for storing a first detergent;
a second storage section for storing a second detergent having a cleaning effect different from that of the first detergent;
a first detergent flow path that supplies the first detergent from the first storage unit to the bathtub;
a second detergent flow path that supplies the second detergent from the second storage unit to the bathtub;
A rinse water flow path for supplying water as rinse water to the bathtub;
a discharge part that is disposed in the bathtub and is connected to the first detergent flow path, the second detergent flow path, and the rinsing water flow path, and is capable of discharging the first detergent, the second detergent, and the rinsing water into the bathtub;
a control unit that controls the supply of the first detergent, the second detergent, and the rinsing water to the bathtub when the bathtub water is drained, thereby cleaning the bathtub;
Equipped with
The control unit is
When the drainage speed is faster than a judgment value, the first detergent is poured into the bathtub, and then the bathtub cleaning is performed in a first mode in which the rinsing water is supplied;
When the drainage speed is equal to or less than the judgment value, the first detergent is poured into the bathtub, the second detergent is poured, and then the bathtub cleaning is performed in a second mode in which the rinsing water is supplied.
A water heater characterized by the above. The water heater according to claim 1, characterized in that, when performing the bathtub cleaning in the second mode, the control unit controls the second detergent to be dispensed after the bathtub water has been completely drained. The control unit controls the waiting time from the completion of drainage of the bathtub water to the start of supply of the rinsing water to be longer in the second mode than in the first mode.
3. The water heater according to claim 1 or 2. The control unit controls the waiting time from the completion of draining the bath water to the start of supplying the rinsing water to be shorter when the drainage speed is fast than when the drainage speed is slow.
The water heater according to any one of claims 1 to 3. Further comprising an operation means for receiving an input of a command related to the operation of the water heater,
5. The water heater according to claim 1, wherein the waiting time from when the bathtub water is completely drained until when the supply of the rinsing water starts is set by a user through the operating means. Further comprising an operation means for receiving an input of a command related to the operation of the water heater,
6. The water heater according to claim 1, wherein the judgment value is configured so that a user can set the judgment value through the operation means. Further comprising a notification means capable of notifying information regarding the operating state of the water heater,
When the bathtub cleaning is performed in the second mode, the control unit notifies the user by the notification means that the bathtub cleaning is being performed in the second mode.
7. The water heater according to claim 1, wherein the water heater is configured as follows. Further comprising a notification means capable of notifying information regarding the operating state of the water heater,
The control unit is configured to notify, by the notification means, that the drain outlet may be clogged when the number of consecutive times when the bathtub cleaning is continuously performed in the second mode exceeds a reference number.
The water heater according to any one of claims 1 to 7. A notification means capable of notifying information regarding an operating state of the water heater;
a means for detecting a remaining amount of the first detergent in the first storage portion and a remaining amount of the second detergent in the second storage portion;
Further comprising:
The control unit is
When the remaining amount of the first detergent becomes less than a first reference amount, the notifying means notifies the user that the first detergent is running low;
When the remaining amount of the second detergent becomes less than a second reference amount, the notifying means notifies that the second detergent is low.
9. The water heater according to claim 1, wherein the water heater is configured as follows. The cleaning device further includes an operation unit for receiving an input for designating a cleaning mode of the bathtub cleaning to the first mode or the second mode,
When the operation means receives an input of designation of the cleaning mode, the control unit executes the bathtub cleaning in the designated cleaning mode regardless of the drainage speed of the bathtub water.
10. The water heater according to claim 1, wherein the water heater is configured as follows. The water heater according to any one of claims 1 to 10, characterized in that the detection means detects the drainage speed based on data on changes in the bathtub water level within a predetermined reference range. The water heater according to any one of claims 1 to 11, characterized in that the control unit is configured to supply the rinsing water after pouring the first detergent into the bathtub and before pouring the second detergent when performing the bathtub cleaning in the second mode.

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