Bath hot water supply device

Abstract

To improve tapping characteristics of hot water supply when a person in a bathroom is detected during cleaning of a reheating passage.SOLUTION: A bath hot water supply apparatus (1) includes hot water supply heating means (14) for heating clean water, a hot water supply passage (22) for supplying the heated hot water, reheating heating means (15) for heating hot water in a bathtub (4), a reheating passage (32) including a circulation pump (31) for circulating hot water in the bathtub to the reheating heating means, a hot water supply passage (25) branched from the hot water supply passage for supplying hot water to the bathtub through the reheating passage, a hot water supply valve (26) for opening and closing the hot water supply passage, and flow rate detection means (27) for the hot water supply passage. The hot water supply device is provided with a flow control valve (24) provided at a branch part of a hot water pouring passage, a control means (20) for controlling a washing operation of a reheating passage for opening a hot water pouring valve at the time of draining a bathtub and circulating clean water or high-temperature hot water as washing water from the hot water pouring passage, and a human detection means (7c) for detecting a person in a bathroom.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hot water supply device for a bath that supplies hot water heated by using the heat of combustion gas to a hot water supply destination including a bathtub. [Background technology]

[0002] Bath water heaters equipped with the function of using the heat of combustion gas to supply hot water and reheat the bathtub water have been widely used. The reheating function involves returning the bathtub water to the bath water heater, heating it, and then returning the heated water to the bathtub. Because the reheating passage for this reheating can become contaminated with dirt and bacteria from the human body, and because the bathtub water is at a temperature suitable for the growth of bacteria, it is preferable to clean the reheating passage after draining the bathtub to keep it clean.

[0003] Therefore, there are known bath water heaters that use, for example, sterilizable high-temperature hot water as cleaning water for the reheating passage, or ozone, which has a sterilizing effect, as in Patent Document 1. If the reheating passage is configured to be automatically cleaned with cleaning water after the bathtub is drained, you can bathe in clean hot water every time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 4-31709 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the higher the temperature of hot water, the less easily gases dissolve in the water. Therefore, when using ozonated water with dissolved ozone as cleaning water, low-temperature tap water is electrolyzed to produce the ozonated water. The low temperature and the sterilizing effect of the ozonated water inhibit the growth of bacteria, etc. Furthermore, when high-temperature hot water is used as cleaning water, the growth of bacteria, etc. is inhibited by using high-temperature hot water for sterilization and cleaning, followed by running low-temperature tap water to lower the temperature.

[0006] On the other hand, there is a bathing style in which the bathtub is soaked, then drained, and finally finished with a shower. In this case, if the reheating passage is automatically cleaned, the hot water used during the bath and remaining in the bath water heater is replaced with low-temperature tap water or high-temperature hot water for cleaning the reheating passage before the shower is used, resulting in a deterioration in the hot water output characteristics of the bath water heater. In other words, when hot water supply starts, the hot water first becomes low-temperature tap water or high-temperature hot water, and then returns to hot water, causing the temperature of the hot water to fluctuate, making it difficult to use comfortably, and there was a demand for improvement.

[0007] Therefore, the present invention aims to improve the hot water supply characteristics when a person in the bathroom is detected while the reheating passage is being cleaned. [Means for solving the problem]

[0008] The bath water heater of the invention of claim 1 comprises a hot water heating means for heating tap water, a hot water supply passage for supplying hot water heated by the hot water heating means, a reheating heating means for heating the hot water in the bathtub, a reheating passage equipped with a circulation pump for circulating the hot water in the bathtub between the reheating heating means, a hot water filling passage branching off from the hot water supply passage and supplying hot water to the bathtub through the reheating passage, a hot water filling valve for opening and closing the hot water filling passage, a flow rate detection means provided in the hot water filling passage, a flow rate adjustment valve provided at the branching point of the hot water filling passage, and a control means for controlling the cleaning operation of the reheating passage that opens the hot water filling valve when the bathtub is drained and circulates tap water or high-temperature hot water heated by the hot water heating means from the hot water filling passage as cleaning water, and is characterized in that it is equipped with a person detection means for detecting a person in the bathroom in which the bathtub is installed, and when the person detection means detects a person in the bathroom during the cleaning operation, the control means adjusts the temperature of the cleaning water to a preset hot water setting temperature and performs cleaning.

[0009] According to the above configuration, if a person in the bathroom is detected during a flush operation of the reheating passage, which uses high-temperature hot water as flush water, the flush water temperature is adjusted to the hot water supply setting temperature. Therefore, the high-temperature hot water in the bath water heater for flush operation is replaced with hot water at about the hot water supply setting temperature, which improves the hot water discharge characteristics when a person in the bathroom uses the hot water supply.

[0010] The bath water heater of the invention of claim 2 comprises a hot water supply heating means for heating tap water, a hot water supply passage for supplying hot water heated by the hot water supply heating means, a reheating heating means for heating hot water in the bathtub, a reheating passage equipped with a circulation pump for circulating the hot water in the bathtub between the reheating heating means, a hot water supply passage branching off from the hot water supply passage and supplying hot water to the bathtub via the reheating passage, a hot water supply valve for opening and closing the hot water supply passage, a flow rate detection means provided in the hot water supply passage, a flow rate adjustment valve provided at the branch point of the hot water supply passage, a flow path switching valve provided midway in the hot water supply passage, and a bypass branching off from the hot water supply passage at the flow path switching valve and connected to the hot water supply passage downstream of the flow path switching valve. This bath water heater has a bypass passage, an ozone water generator installed in the bypass passage, and a control means for controlling the cleaning operation of the reheating passage through which ozone water generated by the ozone water generator is circulated by opening the hot water supply valve when the bathtub is drained and switching the flow path switching valve to the bypass passage side, and is characterized in that it is equipped with a person detection means for detecting a person in the bathroom in which the bathtub is installed, and when a person in the bathroom is detected by the person detection means during the cleaning operation, the control means switches the flow path switching valve to the hot water supply passage side and adjusts the temperature of the hot water heated by the hot water heating means to a predetermined hot water setting temperature to perform cleaning.

[0011] According to the above configuration, if a person is detected in the bathroom during the cleaning operation of the reheating passage using the generated ozone water, the generation of ozone water is stopped and the bath is cleaned with hot water adjusted to the hot water supply setting temperature. Therefore, the low-temperature tap water in the bath hot water supply device for cleaning operation is replaced with hot water at about the hot water supply setting temperature, improving the hot water discharge characteristics when a person in the bathroom uses the hot water supply.

[0012] The bath water heater of the invention of claim 3 is characterized in that, in the invention of claim 2, the cleaning operation is configured to circulate tap water or high-temperature hot water, then circulate the ozone water, and finally circulate tap water, and the control means, when a person is detected in the bathroom while tap water or high-temperature hot water is circulating, circulates a predetermined amount of hot water adjusted to the hot water setting temperature and stops the cleaning operation, and when a person is detected in the bathroom while the ozone water is circulating, switches the flow path switching valve to the hot water supply passage side and circulates a predetermined amount of hot water adjusted to the hot water setting temperature and stops the cleaning operation. With this configuration, the flushing operation is stopped when the hot water discharge characteristics are improved by adjusting the hot water to the hot water supply setting temperature. Therefore, the hot water discharge characteristics can be improved and the waste of flushing caused by hot water that has been adjusted to the hot water supply setting temperature and has reduced cleaning effectiveness can be reduced. [Effects of the Invention]

[0013] According to the hot water supply device for a bath of the present invention, when a person in the bathroom is detected while the reheating passage is being cleaned, the hot water supply characteristics can be improved. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a configuration diagram of a hot water supply system in which a bath hot water supply device according to an embodiment of the present invention is installed. [Figure 2] 10 is a flowchart of a cleaning operation control according to an embodiment. [Figure 3] 10 is a flowchart of a presence detection response operation according to an embodiment. [Figure 4] FIG. 10 is a diagram illustrating the configuration of a hot water supply system showing another example of a hot water supply device for a bath according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, the mode for carrying out the present invention will be described based on examples. [Example]

[0016] First, the configuration of a bath hot water supply device 1 will be described with reference to FIG. Bath water heater 1 is a combustion-type water heater that uses combustion heat to heat clean water supplied through water supply pipe 2 (as indicated by arrow W), and supplies hot water adjusted to a predetermined temperature to the outside through hot water supply pipe 3 (as indicated by arrow HW). This bath water heater 1 performs hot water supply operation, supplying hot water at a preset hot water supply temperature. In addition, bath water heater 1 performs bath filling operation, filling a bathtub 4 installed in the bathroom with hot water at a preset bath temperature up to a preset water level, and performs reheating operation, heating the hot water in bathtub 4 and returning it to bathtub 4 to bring the water to the bath temperature.

[0017] The bath water heater 1 includes a fuel gas supply unit 10, a blower fan 11 that supplies air for combustion, a hot water burner 12 and a reheating burner 13 that burn the fuel gas, a hot water heat exchanger 14 (hot water heating means) that uses the heat of the high-temperature combustion gas generated by combustion to heat the tap water, and a reheating heat exchanger 15 (reheating heating means) that heats the hot water in the bathtub 4. The hot water heat exchanger 14 includes a primary heat exchanger 14a that recovers the sensible heat of the combustion gas and a secondary heat exchanger 14b that recovers the latent heat of the combustion gas. Similarly, the reheating heat exchanger 15 includes a primary heat exchanger 15a and a secondary heat exchanger 15b.

[0018] A water supply temperature sensor 17 for detecting the temperature of the clean water and a water supply flow rate sensor 18 for detecting the flow rate of the clean water are disposed in a water supply passage 16 that supplies clean water from the water supply pipe 2 to the hot water heat exchanger 14. A distribution valve 19 capable of adjusting the distribution ratio is disposed in the water supply passage 16 upstream of the water supply flow rate sensor 18.

[0019] The bath water heater 1 has a control unit 20 (control means) to control various operations based on the temperature detected by the water supply temperature sensor 17 and the flow rate detected by the water supply flow rate sensor 18. The bath water heater 1 is also equipped with a neutralizer 21 containing a neutralizing agent to neutralize and discharge acidic condensed water (drainage) formed when latent heat is recovered in the hot water supply heat exchanger 14 and the reheating heat exchanger 15 and moisture in the combustion gas is condensed. The drainage flows into the neutralizer 21 through a drain passage 21a. The neutralizer 21 discharges the neutralized drainage from a discharge passage 21b to maintain a constant water level and maintain a water-sealed state.

[0020] When water supply flow rate sensor 18 detects a flow rate equal to or greater than a preset minimum operating flow rate, control unit 20 causes combustion in hot water burner 12 to heat the clean water supplied by hot water heat exchanger 14. The heated hot water is supplied to hot water supply passage 22 and mixed with clean water from a water supply bypass passage 23 that is branched off from water supply passage 16 by distribution valve 19 and connected to hot water supply passage 22, thereby adjusting the temperature. Hot water supply passage 22 is equipped with a hot water temperature sensor 22a that detects the temperature of the adjusted hot water, and a hot water supply flow rate adjustment valve 24 (flow rate adjustment valve) that adjusts the flow rate of hot water supplied from hot water supply passage 22. Hot water supply flow rate adjustment valve 24 is normally fully open, and the flow rate is adjusted as necessary.

[0021] A molten metal pouring passage 25 branches off from the molten metal supply passage 22 via a molten metal supply flow rate adjustment valve 24. The molten metal pouring passage 25 is equipped with a molten metal pouring valve 26 that opens and closes the molten metal pouring passage 25, and a molten metal pouring flow rate sensor 27 (flow rate detection means).

[0022] A flow path switching valve 28 is provided midway along the molten metal pouring passage 25. A molten metal pouring bypass passage 29 (bypass passage) branches off from the molten metal pouring passage 25 at this flow path switching valve 28, and this molten metal pouring bypass passage 29 is connected to the molten metal pouring passage 25 downstream of the flow path switching valve 28. The flow path switching valve 28 is switched to either the molten metal pouring passage 25 side or the molten metal pouring bypass passage 29 side so as to select the molten metal pouring passage 25 or the molten metal pouring bypass passage 29 as the flow path for the molten metal pouring. The molten metal pouring bypass passage 29 has an ozone water generator 30 that electrolyzes the molten metal pouring passage 29 and produces ozone water when the flow path switching valve 28 is switched to the molten metal pouring bypass passage 29 side.

[0023] A reheating passage 32 equipped with a circulation pump 31 is connected to the reheating heat exchanger 15 to circulate the hot water in the bathtub 4. The bathtub 4 and the reheating passage 32 are connected by a reheating piping 8 connected to the circulation adapter 4a of the bathtub 4. The reheating passage 32 is composed of a return passage 32a equipped with a circulation pump 31 that returns the hot water in the bathtub 4 to the bath hot water supply device 1 and sends it to the reheating heat exchanger 15, and a bathtub forward passage 32b that returns the hot water that has circulated through the reheating heat exchanger 15 to the bathtub 4. The hot water pouring passage 25 is connected to the return passage 32a via the circulation pump 31. Alternatively, the hot water pouring passage 25 may be connected to the return passage 32a, and a circulation pump 31 may be installed in the return passage 32a downstream of this connection (on the reheating heat exchanger 15 side).

[0024] A water level sensor 33, for example, a water pressure sensor, is disposed in the reheating passage 32 as a water level detection means for detecting the water level in the bathtub 4. A bath temperature sensor 34 for detecting the temperature of the water in the bathtub 4 and a water flow switch 35 as a water flow detection means for detecting the water flow in the reheating passage 32 are provided downstream of the circulation pump 31 in the return passage 32a. The water temperature in the bathtub 4 is detected when the circulation pump 31 is driven, the water in the bathtub 4 flows through the reheating passage 32, and the water flow is detected by the water flow switch 35.

[0025] When hot water is supplied from the bath water heater 1 to, for example, the bathroom faucet 5 or shower 6, hot water adjusted to the set hot water supply temperature is supplied via the hot water supply pipe 3. When filling the bathtub 4, hot water adjusted to the set bath temperature is poured into the bathtub 4 via the hot water pouring passage 25, the reheating passage 32, and the reheating pipe 8. At this time, the hot water from the hot water pouring passage 25 is split into the upstream and downstream sides of the circulation pump 31, and flows through the reheating passage 32 respectively to be supplied to the bathtub 4. The control unit 20 calculates the amount of hot water to be poured into the bathtub 4 based on the flow rate detected by the hot water pouring flow rate sensor 27 and the pouring time, and ends the bath filling operation when the calculated amount of hot water poured reaches the amount corresponding to the set water level.

[0026] In addition, when the bathtub 4 is being reheated, the control unit 20 drives the circulation pump 31 and, while the water flow switch 35 detects water flow, burns the reheating burner 13, causing the hot water in the bathtub 4 circulating through the reheating passage 32 to be heated by the reheating heat exchanger 15 and returned to the bathtub 4. The bath water heater 1 has an operation terminal for starting the reheating operation and for performing various setting operations such as the hot water supply temperature setting, bath temperature setting, and water level setting. This operation terminal, for example, a bathroom remote control 7 installed in the bathroom, is communicatively connected to the control unit 20. In addition to multiple operation buttons, the bathroom remote control 7 is equipped with a display unit 7a that displays setting information related to various operations, an audio output unit 7b, and a human sensor 7c (human detection means) that detects people in the bathroom, allowing it to detect the presence of people in the bathroom and their entry and exit.

[0027] When the water level of bathtub 4 detected by water level sensor 33 drops below the height of circulation adapter 4a and becomes undetectable, control unit 20 detects this as draining of bathtub 4. Then, for example, if the system is set to perform a pipe cleaning operation (hereinafter abbreviated as cleaning operation) in which cleaning water is circulated from hot water supply passage 25 to reheating passage 32 and discharged into bathtub 4 when draining of bathtub 4 is detected, control unit 20 executes the cleaning operation.

[0028] The cleaning operation is performed, for example, in the following order: pre-cleaning, ozone water cleaning, and rinse cleaning. Pre-cleaning sterilizes and washes away dirt by circulating high-temperature hot water. To achieve an ozone concentration that has sufficient sterilizing effect, ozone water cleaning adjusts the distribution valve 19 so that the water supply bypass passage 23 is at its maximum, reduces the flow rate with the hot water flow rate adjustment valve 24, and prevents combustion with the hot water burner 12. Ozone water generated by the ozone water generator 30 is circulated, sterilizing bacteria that cannot be killed by high-temperature hot water. Rinse cleaning washes away stagnant ozone water with tap water, lowering the temperature of the reheating passage 32, etc.

[0029] Next, the cleaning operation control by the control unit 20 will be described based on the flowchart of Fig. 2. In the figure, Si (i = 1, 2, . . . ) represents a step.

[0030] When drainage of the bathtub 4 is detected and cleaning operation control is started, in S1 the cleaning operation step number N is initialized to N=1, and the process proceeds to S2. Step number N corresponds to pre-cleaning with N=1, ozone water cleaning with N=2, and rinsing with N=3. Next, in S2, cleaning with step number N is started, and the process proceeds to S3. For example, in pre-cleaning with step number N=1, the hot water supply valve 26 is opened, combustion of the hot water burner 12 is started, and temperature-adjusted high-temperature hot water is circulated as cleaning water, and the process proceeds to S3.

[0031] Next, in S3, it is determined whether the human sensor 7c has detected a person, i.e., whether the person in the bathroom is not present. If the determination in S3 is No when a person in the bathroom is detected, the process proceeds to S4, where a presence detection response operation is performed, and then the process proceeds to S5. This presence detection response operation will be described with reference to FIG.

[0032] When the occupancy detection response operation is started, it is determined which step of the cleaning operation it is in. First, in S11, it is determined whether the step number N is 1, that is, whether it is a pre-cleaning step. If the determination in S11 is Yes, it is a pre-cleaning step, and the process proceeds to S15.

[0033] If the determination in S11 is No, the process proceeds to S12, where it is determined whether or not the process number N=2, i.e., whether or not the process is an ozone water cleaning process. If the determination in S12 is Yes, it can be determined that the process is an ozone water cleaning process, and the process proceeds to S13, where flow path switching valve 28 is switched to the hot water pouring passage 25 side and hot water supply flow rate adjustment valve 24 is returned to full open, and the process proceeds to S14. On the other hand, if the determination in S12 is No, it can be determined that the process is a rinsing cleaning process with process number N=3, and the process proceeds to S14. Then, in S14, combustion is started in hot water supply burner 12, thereby starting heating of the cleaning water to be supplied to hot water pouring passage 25, and the process proceeds to S15.

[0034] Next, in S15, the temperature of the wash water is adjusted to the set hot water supply temperature, and the process proceeds to S16. In the pre-wash, hot water at a temperature higher than the normally set hot water supply temperature is used as the wash water to enhance the germicidal washing effect, so the temperature of this wash water is lowered to about the hot water supply temperature. In the ozone water wash and rinse wash, unheated clean water is supplied to the hot water supply passage 25, so the distribution ratio of the distribution valve 19 is adjusted to raise the temperature of the wash water to about the hot water supply temperature.

[0035] In S16, it is determined whether the flow of flush water adjusted to the hot water supply temperature setting has reached a predetermined flow rate. The flow rate of flush water is calculated based on the flow rate detected by the hot water supply flow rate sensor 27 and the flow time. The predetermined flow rate (predetermined amount) that serves as the determination criterion is the amount that can replace the water upstream of the hot water supply passage 25 (upstream of the hot water supply flow rate adjustment valve 24 in the hot water supply passage 22) with hot water adjusted to the hot water supply temperature setting. During flushing operation, high-temperature hot water or tap water with a temperature different from the hot water supply temperature setting flows upstream of the hot water supply flow rate adjustment valve 24 in the hot water supply passage 22, so this is replaced with hot water adjusted to the hot water supply temperature setting. For example, the predetermined flow rate can be determined to be the flow rate required for the temperature adjustment to stabilize, which is determined experimentally. Note that the time required for the temperature adjustment to stabilize may be set in advance, and the passage of this time may be determined to be the reaching of the predetermined flow rate.

[0036] If the determination in S16 is No, the process returns to S15 and the flow of wash water continues while adjusting the temperature. If the determination in S16 is Yes, the process proceeds to S17, where the hot water supply valve 26 is closed and the combustion of the hot water burner 12 is stopped to stop the heating and flow of wash water, and the process proceeds to S18. Then, in S18, it is determined whether the human sensor 7c of the bathroom remote control 7 has detected a human, i.e., whether or not the person is present in the room.

[0037] If the determination in S18 is No, the process returns to S18. For example, if the shower 6 is used while occupancy is being detected, hot water used for bathing accumulates from the shower 6 to the hot water supply flow rate adjustment valve 24, and hot water adjusted to the hot water setting temperature accumulates upstream of the hot water supply flow rate adjustment valve 24. Therefore, the temperature of the hot water coming out of the shower 6 quickly becomes approximately the hot water setting temperature and stabilizes, which suppresses temperature fluctuations of the hot water while the shower 6 is in use and improves the hot water discharge characteristics.

[0038] On the other hand, if the determination in S18 is Yes, the presence detection response operation is terminated and the process proceeds to S5 in Fig. 2. Then, in S5, cleaning of step number N is resumed and the process proceeds to S6. Note that cleaning may be resumed from the point of transition to the presence detection response operation, or from the beginning of the step in which the presence detection response operation was performed.

[0039] In S6, it is determined whether the flow of cleaning water in the cleaning of process number N has reached a predetermined flow rate. The flow rate of cleaning water is calculated based on the flow rate detected by the hot water flow rate sensor 27 and the flow time. If the determination in S6 is No, the process returns to S3. If the determination in S6 is Yes, the process proceeds to S7, where the hot water supply valve 26 is closed to end the cleaning of process number N, and the process proceeds to S8. At this time, in the case of pre-cleaning of process number N=1, the combustion of the hot water supply burner 12 is stopped, and in the case of ozone water cleaning of process number N=2, the flow path switching valve 28 is switched to the hot water supply passage 25 side and the hot water supply flow rate adjustment valve 24 is returned to full open. The predetermined flow rate may be the same for pre-cleaning, ozone water cleaning, and rinsing, or may be different.

[0040] In S8, it is determined whether the process number N is less than 3. This is the step to determine whether the rinse cleaning of process number N=3 has been completed. If the determination in S8 is Yes, proceed to S9, in which the process number N is incremented by 1, and return to S2. If the determination in S8 is No, the rinse cleaning has been completed, and the cleaning operation control is terminated.

[0041] For example, as shown in Figure 4, the above-described technology for improving hot water discharge characteristics during a cleaning operation can also be applied to a bath water heater 1A that does not have an ozone water cleaning function but is configured to perform a pipe cleaning operation using high-temperature hot water and tap water as cleaning water. In this case, for example, step number N=1 can be the high-temperature cleaning step and step number N=2 can be the rinse cleaning step, and the cleaning operation can be configured to perform two steps in that order: high-temperature cleaning and rinse cleaning. In either the high-temperature cleaning or rinse cleaning step, if a person is detected in the bathroom, the temperature of the cleaning water can be adjusted to the hot water setting temperature by the presence detection response operation, thereby improving the hot water discharge characteristics during the cleaning operation.

[0042] The operation and effect of the above-described hot water supply device for bath 1, 1A will be explained. The bath water heater 1, 1A is equipped with a human presence sensor 7c (human presence detection means) that detects the presence of a person in the bathroom where the bathtub 4 is installed, and when the human presence sensor 7c detects a person in the bathroom during a flushing operation that uses high-temperature water as the flushing water, the control unit 20 (control means) adjusts the flushing water temperature to a preset hot water supply temperature. Therefore, the high-temperature hot water in the bath water heater 1, 1A for the flushing operation is replaced with hot water at about the hot water supply temperature, improving the hot water discharge characteristics when a person in the bathroom uses the hot water supply.

[0043] The bath water heater 1 is equipped with a hot water supply bypass passage 29 (bypass passage) with an ozone water generator 30 branching off from the hot water supply passage 25 at a flow path switching valve 28, and a human presence sensor 7c (human detection means) that detects people in the bathroom where the bathtub 4 is installed. If a person in the bathroom is detected by the human presence sensor 7c during a cleaning operation using the generated ozone water, the generation of ozone water is stopped and the bath water heater 1 is cleaned with hot water adjusted to the hot water supply setting temperature. Therefore, the low-temperature tap water in the bath water heater 1 for cleaning operation is replaced with hot water at about the hot water supply setting temperature, improving the hot water discharge characteristics when a person in the bathroom uses the hot water supply.

[0044] The flushing operation of the bath water heater 1 is configured to circulate tap water or high-temperature hot water, then ozone water, and finally tap water. If a person is detected in the bathroom while tap water or high-temperature hot water is circulating, the control unit 20 (control means) circulates a predetermined amount of hot water adjusted to the hot water supply temperature and stops the flushing operation. If a person is detected in the bathroom while ozone water is circulating, the control unit 20 switches the flow path switching valve 28 to the hot water supply passage 25, circulates a predetermined amount of hot water adjusted to the hot water supply temperature, and stops the flushing operation. In other words, the flushing operation is stopped with the hot water supply characteristics improved by the hot water adjusted to the hot water supply temperature. This improves the hot water supply characteristics and reduces the waste of flushing caused by hot water adjusted to the hot water supply temperature and having reduced cleaning performance.

[0045] Pre-cleaning may involve circulating unheated clean water after circulating high-temperature hot water to lower the temperature of the hot water upstream of flow path switching valve 28 for the next ozone water cleaning. Pre-cleaning may also involve circulating unheated clean water supplied to hot water supply passage 25 through reheating passage 32 to wash away dirt, followed by sterilization in the next ozone cleaning. The determination of the process in the presence detection response operation may also be based on the combustion status of hot water burner 12 and the switching state of flow path switching valve 28. Those skilled in the art may implement various modifications to the above-described embodiment without departing from the spirit of the present invention, and the present invention encompasses such modifications. [Explanation of symbols]

[0046] 1: Bath water heater 2: Water supply piping 3: Hot water supply piping 4: Bathtub 5: Karan 6: Shower 7: Bathroom remote control 7c: Human sensor (human detection means) 8: Reheating piping 10: Fuel gas supply unit 11: Blower fan 12: Hot water burner 13: Reheat burner 14: Hot water heat exchanger (hot water heating means) 15: Reheating heat exchanger (additional heating means) 16:Water supply passage 17: Water supply temperature sensor 18: Water supply flow sensor 19: Distribution valve 20: Control unit (control means) 21: Neutralizer 22: Hot water passage 23: Water supply bypass passage 24: Flow control valve 25: Pouring passage 26: Meltwater valve 27: Pouring flow rate sensor (flow rate detection means) 28: Flow path switching valve 29: Pouring bypass passage (bypass passage) 30: Ozone water generator 31: Circulation pump 32: Reburning passage 32a: Bathtub return passage 32b: Passage to the bathtub 33: Water level sensor 34: Bathtub temperature sensor 35: Water flow switch

Claims

1. a hot water supply passage for supplying hot water heated by the hot water supply heating means; a reheating heating means for heating the hot water in the bathtub; a reheating passage equipped with a circulation pump for circulating the hot water in the bathtub between the reheating heating means; a hot water filling passage branching from the hot water supply passage and supplying hot water to the bathtub via the reheating passage; a hot water filling valve for opening and closing the hot water filling passage; a flow rate detection means provided in the hot water filling passage; a flow rate adjustment valve provided at the branching point of the hot water filling passage; and a control means for opening the hot water filling valve when the bathtub is drained, and for circulating clean water from the hot water filling passage through the hot water filling passage or high-temperature hot water heated by the hot water supply heating means; a person detection means for detecting a person in the bathroom in which the bathtub is installed; The bath water heater is characterized in that, when the human detection means detects a person in the bathroom during the cleaning operation, the control means adjusts the temperature of the cleaning water to a predetermined hot water setting temperature and performs cleaning.

2. a hot water supply system for a bath, the system comprising: a hot water supply heating means for heating tap water; a hot water supply passage for supplying hot water heated by the hot water supply heating means; a reheating heating means for heating hot water in a bathtub; a reheating passage provided with a circulation pump for circulating the hot water in the bathtub between the reheating heating means; a hot water filling passage branching from the hot water supply passage and supplying hot water to the bathtub via the reheating passage; a hot water filling valve for opening and closing the hot water filling passage; a flow rate detection means provided in the hot water filling passage; a flow rate adjustment valve provided at a branching point of the hot water filling passage; a flow path switching valve provided midway through the hot water filling passage; a bypass passage branching from the hot water filling passage at the flow path switching valve and connected to the hot water filling passage downstream of the flow path switching valve; an ozone water generator provided in the bypass passage; and control means for opening the hot water filling valve when the bathtub is drained, and switching the flow path switching valve to the bypass passage side to control a cleaning operation of the reheating passage through which ozone water generated by the ozone water generator is circulated. a person detection means for detecting a person in the bathroom in which the bathtub is installed; The bath water heater is characterized in that, when the person detection means detects a person in the bathroom during the cleaning operation, the control means switches the flow path switching valve to the hot water supply passage side and adjusts the temperature of the hot water heated by the hot water heating means to a predetermined hot water setting temperature, thereby cleaning.

3. The cleaning operation is configured to circulate tap water or high-temperature hot water, then circulate the ozone water, and finally circulate tap water, The bath water heater device described in claim 2, characterized in that when a person is detected in the bathroom when tap water or high-temperature hot water is circulating, the control means circulates a predetermined amount of hot water adjusted to the hot water supply setting temperature and stops the cleaning operation, and when a person is detected in the bathroom when ozone water is circulating, the control means switches the flow path switching valve to the hot water supply passage side and circulates a predetermined amount of hot water adjusted to the hot water supply setting temperature and stops the cleaning operation.

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