Bath water heater

Abstract

To provide a bath water heater that enables a set water level to be reached when bathing is detected even when hot water in a bathtub is used before the bathing and hot water filling is resumed.SOLUTION: A bath water heater (1) includes: a hot water filling passage (25) for filling hot water in a bathtub (3); a reheating passage (28) for heating hot water in the bathtub; water level detection means (29) for the bathtub; temperature detection means (30) for the hot water in the bathtub; and control means (20) for controlling a bath automatic operation for maintaining a set water level by filling hot water to the bathtub to the set water level at a preset set temperature and maintaining the set temperature through reheating. When the bath automatic operation is started, hot water filling is stopped at a preparation water level lower than the set water level and completion of bath preparation is informed. When bathing is detected at the preparation water level on the basis of fluctuation of the water level, hot water filling is resumed so as to reach the set water level. The control means is configured to perform hot water filling to return to the preparation water level when the water level in the bathtub is lowered before bathing is detected at the preparation water level, and not to perform reheating when the temperature of the hot water in the bathtub is lowered before bathing is detected at the preparation water level.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a bath water supply device configured to heat city water and pour it into a bathtub, and to reheat the bath water in the bathtub.

Background Art

[0002] Conventionally, a bath water supply device having a function of automatic bath operation has been used, in which a preset temperature and a preset water level are set for a bathtub, hot water is poured into the bathtub at the preset temperature until the preset water level, and the water level and the bath water temperature in the bathtub are maintained by pouring hot water and reheating. Since the water level and the bath water temperature in the bathtub are automatically maintained, it is possible to take a comfortable bath even after a certain period of time has passed since the hot water was poured, or when a plurality of users take baths in sequence.

[0003] In automatic bath operation, there may be a case where energy is wasted due to repeated temperature drops of the bath water in the bathtub and temperature increases due to reheating when there is a time gap from when the hot water is poured until the first bath. Therefore, for example, in Patent Document 1, hot water pouring is stopped at a water level lower than the preset water level, and when bathing is detected, the remaining bath water up to the preset water level is poured to reduce wasteful energy consumption.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Bathing styles vary among users, and there are cases where a user takes a bath in the bathtub after using the bath water in the bathtub to take a shower. In this case, as in Patent Document 1, since the bathtub water level lower than the preset water level drops due to taking a shower, it is difficult to set the water level to the preset level even if bathing is detected and hot water pouring is restarted. Therefore, there is a risk of impairing the comfort of the user who has taken a bath.

[0006] Therefore, an object of the present invention is to provide a bathtub water supply device that can be set to a set water level when bathing is detected and hot water injection is restarted even if the hot water in the bathtub is used before bathing.

Means for Solving the Problems

[0007] The bathtub water supply device according to the invention of claim 1 includes a hot water injection passage for injecting heated hot water into the bathtub, a supplementary heating passage for heating the hot water in the bathtub, a water level detection means for detecting the water level of the bathtub, a temperature detection means for detecting the temperature of the hot water in the bathtub, and a control means for controlling an automatic bathtub operation to inject hot water into the bathtub until a set water level is reached at a preset set temperature, maintain the set water level, and perform supplementary heating to maintain the set temperature when the temperature of the hot water in the bathtub drops. When starting the automatic bathtub operation, after injecting hot water to a preparation water level below the set water level, the hot water injection is stopped and the completion of bathtub preparation is notified. Bathing and leaving the bath are detected based on fluctuations in the water level of the bathtub. In the bathtub water supply device that resumes hot water injection to reach the set water level when bathing is detected at the preparation water level, when the water level of the bathtub drops before detecting bathing at the preparation water level, the control means injects hot water to return to the preparation water level, and when the temperature of the hot water in the bathtub drops before detecting bathing at the preparation water level, it is characterized by not performing supplementary heating.

[0008] According to the above configuration, supplementary heating is not performed in the state of the preparation water level, and when the water level of the bathtub drops from the preparation water level before detecting bathing, hot water injection is performed to return to the preparation water level. Therefore, it is possible to reduce wasted energy consumption, perform hot water injection corresponding to the amount of hot water in the bathtub used before bathing, and resume hot water injection corresponding to the amount of hot water corresponding to the difference between the set water level and the preparation water level to reach the set water level.

[0009] The bathtub water supply device according to the invention of claim 2 is the invention of claim 1, wherein when the control means detects bathing at the preparation water level, it resumes hot water injection of an amount of hot water corresponding to the difference between the set water level and the preparation water level, and performs supplementary heating until the set temperature is reached after the completion of this hot water injection. According to the above configuration, when the hot water temperature in the bathtub decreases over time in the state where hot water has been poured up to the preparation water level, and even if hot water is poured at the set temperature until the set water level is reached but the hot water temperature in the bathtub does not reach the set temperature, it can be set to the set temperature by supplementary heating. Therefore, the comfort of bathing can be improved.

[0010] The bathtub hot water supply device according to the invention of claim 3 is, in the invention of claim 1, characterized in that when the control means detects bathing at the preparation water level, it changes the temperature of the hot water to be poured so that the hot water temperature in the bathtub becomes the set temperature at the end of hot water pouring, and resumes pouring of the amount of hot water corresponding to the difference between the set water level and the preparation water level. According to the above configuration, even if the hot water temperature in the bathtub has decreased over time in the state where hot water has been poured up to the preparation water level, the bathtub can be set to the set water level and the set temperature by pouring hot water at the changed temperature.

Advantages of the Invention

[0011] According to the bathtub hot water supply device of the present invention, even if the hot water in the bathtub is used before bathing, it can be set to the set water level when bathing is detected and hot water pouring is resumed.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments for carrying out the present invention will be described based on examples.

Example

[0014] First, the configuration of the bath water heater 1 will be described based on FIG. 1. The bath water heater 1 is a combustion type water heater that heats the city water supplied as indicated by arrow W with the combustion heat of fuel gas and supplies the hot water adjusted to a predetermined temperature to the outside as indicated by arrow HW. However, it may be a water heater having other heat source machines such as a heat pump type heat source machine. This bath water heater 1 performs a hot water supply operation of supplying hot water at a preset hot water supply set temperature. Further, the bath water heater 1 performs hot water filling by pouring hot water at a preset bath set temperature into the bathtub 3 up to a preset set water level, and performs a reheating operation of heating the hot water in the bathtub 3 to the bath set temperature and returning it to the bathtub 3.

[0015] The bath water heater 1 includes a fuel gas supply unit 11, a blower fan 12 that supplies combustion air, a hot water burner 13 and a bath burner 14 that burn fuel gas, and a hot water heat exchanger 15 that heats city water using the heat of the high-temperature combustion gas generated by combustion and a bath heat exchanger 16 that heats the hot water in the bathtub 3. A water supply flow rate sensor 18 for detecting the flow rate of city water is disposed in a water supply passage 17 that supplies city water to the hot water heat exchanger 15. A distribution valve 19 whose distribution ratio can be adjusted is disposed upstream of the water supply flow rate sensor 18.

[0016] In order to control various operations by controlling the distribution ratio of the distribution valve 19 based on the detected flow rate etc. of the water supply flow rate sensor 18, the combustion control of the hot water burner 13, etc., the bath water heater 1 is provided with a control unit 20 (control means). Further, in order to neutralize and discharge the acidic condensed water in which the moisture in the combustion gas has condensed in the hot water heat exchanger 15 and the bath heat exchanger 16, a neutralizer 21 containing a neutralizing agent is equipped.

[0017] When the water supply flow rate sensor 18 detects a flow rate equal to or higher than a preset minimum operating flow rate, the control unit 20 causes the hot water burner 13 to burn and heats the make-up water in the hot water heat exchanger 15. The heated hot water is supplied to the hot water outlet passage 22, and is mixed with the make-up water from the make-up water bypass passage 23 that branches off from the make-up water passage 17 at the distribution valve 19 and is connected to the hot water outlet passage 22, and the temperature is adjusted.

[0018] When the supply destination of the hot water is, for example, a hot water tap (not shown), the hot water adjusted to the set hot water temperature is supplied. When the supply destination of the hot water is the bathtub 3, the hot water adjusted to the bathtub set temperature is poured through the pouring passage 25 provided with the pouring valve 24. The pouring flow rate into the bathtub 3 is detected by a pouring flow rate sensor 26 disposed on the upstream side of the pouring valve 24. The control unit 20 calculates the amount of poured water poured into the bathtub 3 based on this pouring flow rate and the pouring time.

[0019] A reheating passage 28 equipped with a bathtub pump 27 is connected to the bathtub heat exchanger 16 to circulate the hot water in the bathtub 3. The control unit 20 controls a reheating operation in which the hot water in the bathtub 3 flowing through the reheating passage 28 is heated by the bathtub heat exchanger 16 and returned to the bathtub 3 by driving the bathtub pump 27 and causing the bathtub burner 14 to burn.

[0020] The pouring passage 25 is connected to the reheating passage 28 via the bathtub pump 27. When pouring, the pouring valve 24 is opened, and for example, the hot water adjusted to the bathtub set temperature is poured from the pouring passage 25 into the bathtub 3 through the reheating passage 28.

[0021] A water level sensor 29 (water level detection means) for detecting the water level of the bathtub 3 by water pressure is disposed in the pouring passage 25. The control unit 20 detects bathing and leaving the bath based on the fluctuation of the water level of the bathtub 3. A bathtub temperature sensor 30 (temperature detection means) for detecting the hot water temperature of the bathtub 3 is disposed on the downstream side of the bathtub pump 27 in the reheating passage 28. The hot water temperature of the bathtub 3 is detected in a state where the bathtub pump 27 is driven and the hot water in the bathtub 3 is circulated through the reheating passage 28. Note that the water level sensor 29 may be disposed in the reheating passage 28.

[0022] The bath water supply device 1 has an operation terminal for performing various setting operations such as the start operation of the reheating operation, the set hot water temperature, the set bath temperature, and the set water level. As this operation terminal, for example, a bathroom remote control 4 installed in the bathroom and a kitchen remote control 5 installed in the kitchen, for example, are communicatively connected to the control unit 20. The bathroom remote control 4 and the kitchen remote control 5 are equipped with display units 4a and 5a for displaying setting information and the like, and voice output units 4b and 5b in addition to a plurality of operation buttons. Further, the bathroom remote control 4 is equipped with a human sensor 4c for detecting a user in the bathroom.

[0023] Next, the automatic bath operation of the bath water supply device 1 will be described based on the flowcharts of FIGS. 2, 3, and 4. Si (i = 1, 2, ···) in the figure represents a step. When the start operation of the automatic bath operation is performed from the operation terminal, the control unit 20 starts the automatic bath operation. In the automatic bath operation, hot water is poured into the bathtub 3 until the set water level is reached at the preset set bath temperature, this set water level is maintained, and when the hot water temperature in the bathtub 3 drops, reheating is performed to maintain the set bath temperature.

[0024] When the automatic bath operation is started, first, bath preparation for pouring hot water into the bathtub 3 is performed at S1 in FIG. 2. When the bath preparation is started, as shown in FIG. 3, the preset set water level and set bath temperature (hereinafter referred to as the set temperature) of the bathtub 3 are acquired at S11, and the process proceeds to S12. Then, the preparation water level is set at S12, and the process proceeds to S13. As shown in FIG. 1, the preparation water level (WLp) of the bathtub 3 is a water level lower than the set water level (WLs), and is, for example, 20% lower than the set water level. Incidentally, for example, during the trial operation of the bath water supply device 1, the control unit 20 learns the relationship between the hot water pouring amount and the water level in the bathtub 3, or the relationship between the hot water pouring amount and the water level is set in the control unit 20.

[0025] Next, in S13 of FIG. 3, pouring of hot water at the set temperature is started and the process proceeds to S14. Then, in S14, based on the amount of water poured into the bathtub 3 or the detected water level of the water level sensor 29, it is determined whether the preparation water level has been reached. If the determination in S14 is No, pouring continues and the process returns to S14. If the determination in S14 is Yes, the process proceeds to S15.

[0026] Next, in S15, pouring is stopped and the process proceeds to S16. In S16, it is notified that the bath preparation is complete and the process proceeds to S17. For example, the completion of bath preparation is notified to the user by the display on the display units 4a and 5a of the bathroom remote controller 4 and the kitchen remote controller 5, and the sound output from the sound output units 4b and 5b. Then, in S17, the remaining amount of water to be poured is calculated and the process proceeds to S18. The remaining amount of water to be poured is the amount of hot water corresponding to the difference between the set water level and the preparation water level (WLs - WLp).

[0027] Next, in S18, the water level of the bathtub 3 is acquired and the process proceeds to S19. Then, in S19, it is determined whether the water level of the bathtub 3 has dropped by β or more from the preparation water level. β can be set as appropriate and is set to, for example, 1 cm. When a user who has recognized the completion of bath preparation by the notification in S16 uses the hot water in the bathtub 3 to take a shower before taking a bath in the bathtub 3, the water level of the bathtub 3 becomes, for example, a water level (WLu) that has dropped by β or more from the preparation water level (WLp) in FIG. 1. This is the step of determining this drop in water level.

[0028] If the determination in S19 of FIG. 3 is Yes, the process proceeds to S20. In S20, the replenishment amount up to the preparation water level corresponding to the difference between the preparation water level and the current water level (WLp - WLu) is calculated and the process proceeds to S21. Then, in S21, pouring of the replenishment amount is executed at the set temperature and the process proceeds to S22. On the other hand, if the determination in S19 is No, pouring is not performed and the process proceeds to S22.

[0029] Next, at S22, it is determined whether or not the user's bathing in the bathtub 3 is detected based on the fluctuation of the water level in the bathtub 3. Since the water level in the bathtub 3 rises during bathing, when the water level detected by the water level sensor 29 becomes, for example, a certain level higher than the preparation water level, it is determined that bathing has been detected. If the determination at S22 is No, the process returns to S18. If the determination at S22 is Yes, the process proceeds to S23.

[0030] Next, at S23, the hot water injection is restarted, and hot water injection of the remaining hot water injection amount calculated at S17 is performed with hot water at the set temperature, and the process proceeds to S24. Then, at S24, the supplementary heating is started, and the process proceeds to S25. This supplementary heating is performed to heat up to the set temperature because when the hot water temperature in the bathtub 3 has decreased due to the passage of time from the completion of the bath preparation to the detection of bathing, the hot water temperature in the bathtub 3 will not reach the set temperature with the hot water injection of the remaining hot water injection amount.

[0031] At S25, the hot water temperature in the bathtub 3 is acquired, and the process proceeds to S26. Then, at S26, it is determined whether or not this hot water temperature is equal to or higher than the set temperature. If the determination at S26 is No, the supplementary heating is continued and the process returns to S25. If the determination at S26 is Yes, the process proceeds to S27. At S27, the supplementary heating is terminated and the bath preparation is terminated, and the process returns.

[0032] Here, as shown in FIG. 4, the hot water injection temperature can also be changed based on the hot water temperature in the bathtub 3 so that the set temperature is reached simultaneously with the completion of the hot water injection of the remaining hot water injection amount. Since S11 to S22 are the same as those in FIG. 3, the description is omitted. At S33 after the bathing detection at S22, the hot water temperature in the bathtub 3 is acquired, and the process proceeds to S34. Next, at S34, for example, based on the set water level, the set temperature, the hot water temperature in the bathtub 3, and the remaining hot water injection amount, the hot water injection temperature that can make the hot water temperature in the bathtub 3 reach the set temperature simultaneously with the completion of the hot water injection of the remaining hot water injection amount is calculated, and the process proceeds to S35. Then, at S35, the hot water injection is restarted, and the hot water injection of the remaining hot water injection amount is performed at the calculated hot water injection temperature, and the bath preparation is terminated, and the process returns. Thereby, the arrival at the set temperature can be accelerated compared to the case where the supplementary heating is performed after the hot water injection.

[0033] When the bath preparation is completed, the process proceeds to S2 in FIG. 2, and at S2, the water level and hot water temperature in the bathtub 3 are maintained. When this water level and temperature maintenance is started, as shown in FIG. 5, the water level and hot water temperature in the bathtub 3 are acquired at S41, and the process proceeds to S42. Then, at S42, since it is not possible to detect whether the hot water in the bathtub 3 has decreased because the water level in the bathtub 3 rises during the user's bath, it is determined whether bath detection has been performed. If the determination at S42 is No, the process proceeds to S43, and at S43, it is determined whether the water level in the bathtub 3 has dropped by γ or more from the set water level. γ can be set as appropriate, for example, it is set to 1 cm.

[0034] If the determination at S43 is Yes, the process proceeds to S44, and at S44, the maintenance amount required to return to and maintain the set water level is calculated, and the process proceeds to S45. Then, at S45, pouring of hot water with the set temperature is executed according to the maintenance amount, and the process proceeds to S46. On the other hand, if the determination at S42 is Yes, it is not possible to determine the drop in the water level of the bathtub 3, and if the determination at S43 is No, since the water level of the bathtub 3 has not dropped, the process proceeds to S46 without pouring hot water.

[0035] Next, at S46, it is determined whether the hot water temperature in the bathtub 3 has dropped by δ or more from the set temperature. δ can be set as appropriate, for example, it is set to 1 °C. If the determination at S46 is Yes, the process proceeds to S47, and at S47, supplementary heating is started and the process proceeds to S48. Then, at S48, the hot water temperature in the bathtub 3 is acquired and the process proceeds to S49, and at S49, it is determined whether this hot water temperature is equal to or higher than the set temperature. If the determination at S49 is No, the supplementary heating is continued and the process returns to S48. If the determination at S49 is Yes, the process proceeds to S50, and at S50, the supplementary heating is ended and the water level and temperature maintenance is ended, and the process returns.

[0036] Even in maintaining the water level and temperature, for example, as shown in FIG. 6, the pouring temperature can be changed to perform pouring of the maintaining amount. Since S41 to S44 and S46 to S50 are the same as those in FIG. 5, the description thereof is omitted. In S55 after calculating the maintaining amount in S44, for example, based on the set temperature, the set water level, the hot water temperature in the bathtub 3, and the calculated maintaining amount, the pouring temperature that can be set to the set temperature simultaneously with the completion of pouring of the maintaining amount is calculated, and the process proceeds to S56. This pouring temperature may be the same as the set temperature. Then, in S56, pouring of the maintaining amount is performed at the calculated pouring temperature to end the water level and temperature maintenance, and return. Thereby, the arrival at the set temperature can be accelerated compared to the case of FIG. 5.

[0037] When the water level and temperature maintenance ends, the process proceeds to S3 in FIG. 2, and it is determined whether there is a setting change operation for the automatic bathtub operation in S3. For example, when the set temperature is increased and the determination in S3 is Yes, the process returns to S2 to set the temperature to the changed set temperature. When the determination in S3 is No, the process proceeds to S4, and it is determined whether there is an end operation for the automatic bathtub operation in S4. When the determination in S4 is No, the automatic bathtub operation is continued and the process returns to S2. When the determination in S4 is Yes, the automatic bathtub operation ends. Note that S3 to S4 may be repeated at a predetermined time so as to shift to the step of maintaining the water level and temperature at a predetermined time cycle.

[0038] The operation and effect of the above-described bathtub water supply device 1 will be described. The bathtub water supply device 1 performs an automatic bathtub operation in which hot water is poured into the bathtub 3 until the set water level is reached at a preset set temperature to maintain the set water level, and reheating is performed when the hot water temperature in the bathtub 3 drops to maintain the set temperature. When this automatic bathtub operation is started, after pouring hot water to a preparation water level below the set water level, pouring is stopped and it is notified that the bathtub preparation is complete. When the user's bathing is detected at the preparation water level, pouring is restarted so as to reach the set water level. Then, when the water level in the bathtub 3 drops before bathing is detected at the preparation water level, pouring is performed to return to the preparation water level, but when the hot water temperature in the bathtub 3 drops before bathing is detected at the preparation water level, reheating is not performed.

[0039] Since reheating is not performed at the ready water level, it is possible to reduce wasteful energy consumption. Further, when the water level in the bathtub 3 drops from the ready water level before bathing detection, hot water is poured to return it to the ready water level. Therefore, after bathing detection, pouring of the amount of hot water corresponding to the difference between the set water level and the ready water level can be restarted to reach the set water level.

[0040] When the control unit 20 detects bathing at the ready water level, it restarts hot water pouring and pours the amount of hot water corresponding to the difference between the set water level and the ready water level, and performs reheating until the set temperature is reached after the completion of this hot water pouring. As time passes in the state where hot water has been poured up to the ready water level and the hot water temperature in the bathtub 3 does not reach the set temperature even if hot water is poured at the set temperature until the set water level is reached, it can be set to the set temperature by reheating. Therefore, the comfort of bathing can be improved.

[0041] When the control unit 20 detects bathing at the ready water level and restarts hot water pouring, it can change the temperature of the hot water to be poured so that the hot water temperature in the bathtub 3 becomes the set temperature at the end of hot water pouring, and pour the amount of hot water corresponding to the difference between the set water level and the ready water level. Therefore, even if the hot water temperature in the bathtub 3 has dropped due to the passage of time in the state where hot water has been poured up to the ready water level, the bathtub 3 can be set to the set water level and the set temperature by pouring hot water at the changed temperature, and the comfort of bathing can be improved.

[0042] In addition, those skilled in the art can implement the present invention in various modified forms without departing from the spirit of the present invention, and the present invention includes such modified forms.

Explanation of Reference Numerals

[0043] 1: Bathtub water supply device 3: Bathtub 4: Bathroom remote control 5: Kitchen remote control 11: Fuel gas supply unit 12: Blower fan 13: Hot water supply burner 14: Bathtub burner 15: Hot water supply heat exchanger 16: Bath heat exchanger 17: Water supply passage 18: Water supply flow sensor 19: Distribution valve 20: Control unit (control means) 21: Neutralizer 22: Hot water outlet passage 23: Water supply bypass passage 24: Pouring valve 25: Pouring passage 26: Pouring flow sensor 27: Bath pump 28: Afterburner passage 29: Water level sensor (water level detection means) 30: Bath temperature sensor (temperature detection means)

Claims

1. A hot water supply device for a bathtub, comprising: a hot water pouring passage for pouring heated hot water into the bathtub; a reheating passage for heating the hot water in the bathtub; a water level detection means for detecting the water level of the bathtub; a temperature detection means for detecting the temperature of the hot water in the bathtub; and a control means for controlling an automatic bathtub operation to pour hot water into the bathtub until a set water level is reached at a preset set temperature, maintain the set water level, and perform reheating to maintain the set temperature when the temperature of the hot water in the bathtub drops. When the automatic bathtub operation is started, hot water is poured to a preparation water level below the set water level, then the pouring is stopped and it is notified that the bathtub preparation is complete. Bathing and leaving the bath are detected based on fluctuations in the water level of the bathtub. When bathing is detected at the preparation water level, hot water pouring is restarted so as to reach the set water level. In the hot water supply device for a bathtub, when the water level of the bathtub drops before bathing is detected at the preparation water level, the control means performs hot water pouring to return to the preparation water level, and when the temperature of the hot water in the bathtub drops before bathing is detected at the preparation water level, the control means does not perform reheating. The hot water supply device for a bathtub is characterized in that.

2. When bathing is detected at the preparation water level, the control means restarts hot water pouring of a hot water volume corresponding to the difference between the set water level and the preparation water level, and performs reheating until the set temperature is reached after the completion of this hot water pouring. The hot water supply device for a bathtub according to Claim 1, characterized in that.

3. When bathing is detected at the preparation water level, the control means changes the temperature of the hot water to be poured so that the temperature of the hot water in the bathtub becomes the set temperature at the end of the hot water pouring, and restarts hot water pouring of a hot water volume corresponding to the difference between the set water level and the preparation water level. The hot water supply device for a bathtub according to Claim 1, characterized in that.

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