JP2024029246A - Water pouring method, water pouring system and water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a drain residual by water pouring after a drain discharge, and to promote a user to perform the drain discharge.

SOLUTION: A water pouring method commonly uses a drain discharge of a drain tank (10) for accumulating drains (D) which are generated by a heat exchange. The drains are discharged to a bathtub from the drain tank at the water discharge timing of the bathtub (14), or at timing at which the drains in the drain tank exceed a reference level, and a water flow is not generated by the pump circulation of a bathtub water, then, after the drains are discharged, water is poured into the bathtub, and after the water is poured into the bathtub at a constant volume, it is determined whether or not a circulation port of the bathtub is partially immersed in the water, or entirely immersed in the water. When the circulation port of the bathtub is partially or entirely immersed in the water at a constant volume, the pouring of the water to the bathtub is continued, the water is thereby poured into the bathtub up to a set water level, and the water is boiled up to a set temperature.

SELECTED DRAWING: Figure 7

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates, for example, to a water injection technique that includes discharging condensate generated in a heat exchanger when heat exchanges heat of combustion of fuel gas to water supply.

Drainage is generated in the heat exchanger when the combustion heat of fuel gas is exchanged with water supply, etc., but in high-efficiency water heaters that are equipped with a secondary heat exchanger that recovers the latent heat of combustion heat, the generation of drainage is noticeable. be. After this drain is neutralized with a neutralizer, it is stored in a drain tank, and when the bathtub stopper is opened, it is discharged through the bathtub.
Regarding this drain discharge, it is known to dilute or neutralize the drain in a drain tank and then drain it through a bathtub (for example, Patent Document 1). It is known that drain from a drain tank is drained through a reheating pipe at a predetermined drain timing (for example, Patent Document 2).

Japanese Patent Application Publication No. 2005-265228 Japanese Patent Application Publication No. 2009-270798

By the way, when drain from a drain tank is discharged through a bathtub, the bathtub is simply used as a drainage path, and the drain does not mix into the bathtub water. For this reason, when draining the drain from the drain tank through the circulation path into the bathtub and draining it from the bathtub's drain port into the drain pan, after draining the drain, by supplying water to the bathtub through the circulation path, the drain can be drained from the circulation path piping and the bathtub. Measures are being taken to ensure that no residue remains.
This type of drainage is based on the assumption that the bathtub stopper is open, and if the bathtub stopper is closed by mistake, the draining water may remain in the circulation path or inside the bathtub, causing it to mix with the bathtub water. There is a problem with this. Even if a predetermined amount of water or hot water is supplied for cleaning, if the valve is closed, drain cannot be discharged from the bathtub. If the user closes the bathtub valve and switches to automatic hot water supply without noticing this drain discharge, there is a risk that this kind of drain may remain.If the drain gets mixed into the bath water, the drain is colorless and transparent, so the bathtub There is a problem in that it is not possible to determine whether or not condensate is mixed in the water.
By the way, the inventor of the present application poured a certain amount of water when discharging the drain into the bathtub, also to clean the pipe through which the drain passed, and when the next automatic hot water filling was performed, the amount of water poured in was smaller than the initial water level. We have obtained knowledge that it is possible to confirm whether there is residual drain by checking whether or not it exceeds the circulation port. However, based on this knowledge, we obtained the knowledge that when a certain amount of water is supplied, the water level varies depending on the volume of the bathtub and the shape inside the bathtub, so the judgment results will vary and it may not be possible to confirm the residual drainage. .

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to determine whether drain remains by pouring water after draining, and to prompt the user to drain the drain.
In view of the above problems, another object of the present invention is to determine the remaining amount of drain by submerging part or all of the circulation port with a certain amount of water, which is not affected by the volume of the bathtub or the shape inside the bathtub. The purpose is to improve the accuracy of drainage and inject water.

In order to achieve the above object, according to one aspect of the water injection method of the present invention, there is provided a water injection method that uses drain discharge from a drain tank that collects drain generated during heat exchange, the water injection method being based on the draining timing of the bathtub or the drainage timing of the drain tank. discharging the condensate from the drain tank into the bathtub at a timing when the condensate exceeds a reference level and no water flow is generated during pump circulation of the bathtub water; and pouring water into the bathtub after discharging the condensate; After pouring a certain amount of water into the bathtub, determining whether part or all of the circulation opening of the bathtub is submerged in water; In this case, the method includes a step of continuing to pour water into the bathtub to a set water level and boiling the water to the set temperature.
In this water filling method, if part or all of the circulation port of the bathtub is not submerged in water, the circulation pump is driven for a predetermined period of time to drain the remaining water in the circulation path, and then water is poured to the set water level of the bathtub. It may also include a step of boiling to a temperature.
In this water filling method, if part or all of the circulation port of the bathtub is submerged due to pouring a certain amount of water into the bathtub when discharging the drain, alert information is output, and after draining the bathtub, the bathtub is filled with water. It may also include a step of allowing water to be poured into the container.

In order to achieve the above object, according to one aspect of the water injection system of the present invention, there is provided a water injection system that uses drain discharge from a drain tank that collects drain generated during heat exchange, the water injection system including a bathtub and the drain collected in the drain tank. a level sensor for detecting the level of the drain, a drain discharge part for discharging the drain from the drain tank into the bathtub, and a circulation system used for pouring water into the bathtub, circulating bathwater in the bathtub, and discharging the drain into the bathtub. a circulation pump that circulates the bathtub water through the circulation path, a water injection section that injects water into the bathtub through the circulation path, and a heat exchanger that exchanges heat of combustion of the fuel gas to the water injection or the bathtub water. , discharging the condensate from the drain tank into the bathtub at the timing of draining the bathtub, or at a timing when the drain of the drain tank exceeds a reference level and no water flow is generated during pump circulation of the bathtub water, and discharging the drain; After that, water is poured into the bathtub, and after pouring a certain amount of water into the bathtub, it is determined whether a part or all of the circulation port of the bathtub is submerged in water, and with the certain amount of water being poured, the circulation port of the bathtub is If the bathtub is partially or completely submerged in water, the bathtub continues to be filled with water to a set water level and is heated to a set temperature.
In this water injection system, if a part or all of the circulation port of the bathtub is not submerged in water, the control section drives the circulation pump for a predetermined period of time to drain the residual water in the circulation path, and then controls the flow of water in the bathtub. You can also pour water to the set water level and boil it to the set temperature.
In this water injection system, the control unit outputs alert information when a certain amount of water is poured into the bathtub when discharging the drain and a part or all of the circulation port of the bathtub is submerged in water, and After draining, water may be allowed to be poured into the bathtub.

In order to achieve the above object, one aspect of the water heater of the present invention is a water heater that includes the water injection system.

According to the present invention, any of the following effects can be obtained.
(1) By injecting water after draining, it is possible to determine whether there is any remaining condensate, and by notifying the user or stopping water injection, the user is prompted to drain the condensate, and water can be poured while preventing condensate from remaining.
(2) If the bathtub faucet is closed, if the user opens the bathtub faucet in response to an alert output, condensate can be discharged from the bathtub after a certain amount of water has been poured into the bathtub, and water can be poured into the bathtub without condensate. It is possible.
(3) Since the drain remaining in the bathtub is diluted by the initial water filling, opening the bathtub valve allows draining, which also serves as a bathtub purification, and water can be poured into the bathtub without draining.

It is a figure showing the drain discharge device concerning one embodiment. It is a flowchart which shows the processing process of drain discharge. A is a diagram showing the water level setting of the bathtub according to the first embodiment, and B is a diagram showing a bathtub data table. A is a front view showing the drain tank, and B is a side view showing the drain tank. 1 is a diagram illustrating a hot water supply reheating device according to Example 1. FIG. It is a figure which shows an example of the control part of a hot water supply reheating apparatus. It is a flowchart which shows the processing procedure 1 of drain discharge. A is a diagram showing the initial water injection operation, and B is a diagram showing the state before water injection. A is a diagram showing a state immediately before water is poured, and B is a diagram showing a state in which water remains in the bathtub. It is a flowchart which shows the processing procedure 1 of fully automatic operation. It is a flowchart which shows the process procedure 2 of fully automatic operation. A is a diagram showing a normal drainage state, and B is a diagram showing an abnormal drainage state. 7 is a flowchart showing a drain discharge processing procedure according to the second embodiment. It is a figure which shows the hot water supply reheating apparatus based on Example 3.

[One embodiment]
FIG. 1 shows a drain discharge device in a water injection system according to an embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to this configuration.
This drain discharge device 2 is equipped with a drain discharge section 4, a water injection section 6, and an alert output section 8, and drain D generated by heat exchange is stored in a drain tank 10 and discharged from a bathtub 14 through a circulation path 12.

The drain discharge unit 4 is configured, for example, at the timing of draining the bathtub 14 when the bathtub faucet 16 is opened, or when the drain D exceeds the reference level Dref, which is an example of the drain tank 10, and the water flow is generated by the circulation of the bathtub water BW by the circulation pump 18. Discharge the drain at any of the drain timings that have been confirmed. The presence or absence of water flow generation is detected by a water flow switch 20, which is an example of water flow detection means.
After the drain D is discharged, the water injection unit 6 injects a certain amount of water. A certain amount of water is poured into the empty bathtub 14 with the bathtub stopper 16 closed to also clean the drain discharge circuit, which will be described later. Even if water is poured, if a certain amount of water is added, the amount of water will submerge part or all of the circulation port 22. This water injection may be either water supply before heating or hot water after heating.
The alert output unit 8 outputs an alarm to the bathtub 14 if a part or all of the circulation port 22 is submerged due to the initial water injection into the bathtub 14 by the water injection unit 6, that is, if a water flow is generated due to the circulation of the bathtub water BW by the circulation pump 18. Alert information indicating that drain D remains inside is output. The presence or absence of water flow may be confirmed by the output of the water flow switch 20.

<Drain discharge process>
FIG. 2 includes a drain discharge and a discharge abnormality detection process according to an embodiment. This processing procedure is an example of a drain discharge method in which drain D generated by heat exchange is stored in the drain tank 10 and discharged from the bathtub 14 through the circulation path 12. Includes water level judgment and output of alert information.
Regarding the discharge of drain D, it is determined whether it is the first discharge timing or the second discharge timing (S11). The first draining timing is the timing of draining the bathtub 14 when the bathtub stopper 16 is opened. The second discharge timing is the timing when it is confirmed that the drain D exceeds the above-mentioned reference level Dref of the drain tank 10 and that no water flow is generated in the pump circulation of the bathtub water BW. This timing comes, for example, when the drain D exceeds the upper level Href (FIGS. 4 and 5) of the reference level Dref.

If it is the first or second discharge timing (YES in S12), the drain D in the drain tank 10 is discharged into the bathtub 14 from the drain discharge circuit including the circulation path 12 (S13). In this case, a drain discharge circuit is established from the drain tank 10 through the circulation path 12 to the circulation port 22 to perform drain discharge. The drain discharge circuit is a drain D path from the drain tank 10 to the bathtub 14 or from the drain tank 10 to the outside of the bathtub 14 when the bathtub plug 16 is opened.
It is determined whether the drain D has been discharged (S14), and if the drain D has been discharged from the drain tank 10 (YES in S14), a certain amount equivalent to, for example, 3 cm of the bathtub water level is supplied from the water injection part 6. A water amount W1 is injected to clean the drain discharge circuit including the circulation path 12 (S15). This completes drain discharge.

When water is poured after draining, a certain amount of water is initially poured into the bathtub 14 from the water injection section 6 (S16). This initial amount of water is smaller than the amount of water that submerges part or all of the circulation port 22 by a water amount W2 corresponding to, for example, 2 cm of the bathtub water level. At the time of water filling, the bathtub stopper 16 is in a closed state.

It is determined whether part or all of the circulation port 22 is submerged in water due to this water injection (S17). This determination may be made, for example, based on the presence or absence of water flow due to the circulation of the bathtub water BW by the circulation pump 18.
If part or all of the circulation port 22 is not submerged (NO in S17), the drain D has been discharged from the bathtub 14, so no alert information is output (S18). Further, if part or all of the circulation port 22 is submerged in water (YES in S17), an alert indicating that the drain D remains in the bathtub 14 or an alert indicating that water injection has been stopped is output (S19). This alert can prompt the user to open the bathtub stopper 16, that is, to drain the bathtub.

<Effects of one embodiment>
According to this embodiment, the following effects can be obtained.
(1) During the next water injection, that is, at the time of filling the water, an alarm will alert you to the remaining condensate from the previous discharge during the initial hot water supply.
(2) If there is an alarm indicating that water injection has stopped or that drainage remains, the bathtub can be drained at that point, and drainage can be prevented from remaining.

<Tub water level setting>
FIG. 3A shows the water level setting of the bathtub according to the first embodiment. In FIG. 3A, the same parts as in FIG. 1 are given the same reference numerals.
A circulation port 22 to which the circulation path 12 (FIG. 1) is connected is provided on the side surface of the bottom side of the bathtub 14. The height of the circulation port 22 is set so that its center is at a certain height, for example, about 15 [cm] from the bottom surface 26 of the bathtub.

In the bathtub 14, an initial water level Lini, a reference water level Lst, and a plurality of set water levels Ln at height intervals, for example, L1, L2, L3, . . . L11, are set from the bathtub bottom surface 26.
The initial water level Lini is a water level near the center of the circulation port 22, and is such a level that the return pipe 12-1 of the circulation path 12 is submerged.
The reference water level Lst is set at a certain height, for example, about 8 cm from the initial water level Lini.
The set water level L1 is set to a certain height, for example, about 3 [cm] from the reference water level Lst, and each set water level L1, L2, L3...L11 has a certain width in the height direction, for example, 3 cm. It is about [cm]. The bathtub water level may be selected from the set water levels L1, L2, L3...L11.

The height from the bathtub bottom 26 to the set water level L1 is:
Height of set water level L1 = 15 [cm] + 8 [cm] + 3 [cm]
=26 [cm] ...(1)
The height from the bathtub bottom 26 to the set water level L11 is:
Height of set water level L11 = 15 [cm] + 8 [cm] + 3 [cm] x 11
=56 [cm] ...(2)
It is.

If the resolution of the bathtub water level sensor 24 is 1 Bit = 0.2125 [cm], the height of each set water level L1 to L11 is 3 [cm], so 14 Bit = 2.975 [cm]. .
The initial water amount from the bathtub bottom 26 to the initial water level Lini including the water amount in the piping is Vini, the reference water amount from the initial water level Lini to the reference water level Lst is Vst, and the water amount from the reference water level Lst to the set water level L1 (=Ld) is Vd. do. These water amounts have different values depending on the piping and the bathtub 14.

<Bathtub data table 28>
FIG. 3B shows a bathtub data table. This bathtub data table 28 is a database of bathtub data, and stores installation information, water level information, etc. of the bathtub 14.
This bathtub data table 28 stores bathtub information 30 and water level information 32, and the water level information 32 stores initial water level information 32-1, reference water level information 32-2, and set water level information 32-3.
The bathtub information 30 stores information such as the installation status and size of the bathtub 14.

The initial water level information 32-1 stores the amount of water Vini from the bathtub bottom 26 to the initial water level Lini, including the amount of water in the piping. The water amount Vini is a measurement value of the bathtub water level sensor 24.
The reference water level information 32-2 stores the reference water amount Vst from the initial water level Lini to the reference water level Lst. This reference water amount Vst is a value measured by the bathtub water level sensor 24.
The set water level information 32-3 stores a water amount Vd, which is a unit water amount for each set water level from the reference water level Lst to the set water level L11.
This information is used for fully automatic hot water supply control including drain discharge.

<Drain tank 10>
4A shows a longitudinal cross section of the drain tank 10, and FIG. 4B shows a cross section taken along the line IVB-IVB of FIG. 4A. In this first embodiment, the upper level Href and the lower level Lref are set as the reference level Dref described above.
This drain tank 10 is equipped with an introduction port 34, a discharge port 36, an overflow port 38, and a drain level sensor 40. The neutralized drain D is led from the introduction port 34 to the drain tank 10, is stored therein, and is discharged from the discharge port 36. When the drain D exceeds the upper limit level (overflow level) U, it is discharged to the outside of the drain tank 10 from the overflow port 38.
The drain level sensor 40 is a sensor that detects the water level of the drain D accumulated in the drain tank 10. This drain level sensor 40 includes a common electrode 40-1, a lower level detection electrode 40-2, an upper level detection electrode 40-3, and an upper level detection electrode 40-4. The common electrode 40-1 is set at a submerged position in the drain D. In this drain tank 10, the lower level Lref of the drain D is detected by the common electrode 40-1 and the lower level detection electrode 40-2, and the upper level Href of the drain D is detected by the common electrode 40-1 and the upper level detection electrode 40-3. Ru. The upper limit level detection electrode 40-4 detects an upper limit level U higher than the upper level Href, and this upper limit level U is, for example, an overflow level.

<Hot water reheating device 42>
FIG. 5 shows a hot water reheating device 42 according to a first embodiment of a water injection system including the drain discharge device 2 described above. This hot water reheating device 42 is an example of a hot water supply device. This hot water reheating device 42 is provided with a hot water supply function for general hot water supply to areas other than the bathtub 14, a hot water supply function for pouring hot water into the bathtub 14, and a function for reheating the bathtub water BW.

This hot water reheating device 42 is provided with a hot water supply combustion chamber 44-1 and a reheating combustion chamber 44-2. The hot water supply combustion chamber 44-1 is equipped with a primary heat exchanger 48 and a secondary heat exchanger 50. The primary heat exchanger 48 exchanges heat, mainly sensible heat, of the combustion exhaust gas 54 obtained by combustion in the burner 52 with the feed water W, and the secondary heat exchanger 50 mainly exchanges latent heat of the combustion exhaust gas 54, which has passed through the primary heat exchanger 48. Heat exchanges with water supply W.
The reheating combustion chamber 44-2 is equipped with a heat exchanger 56. The heat exchanger 56 exchanges sensible heat of the combustion exhaust 60 obtained by combustion in the burner 58 with the bath water BW. The heat exchangers 48, 50, and 56 are capable of bidirectional operation or independent operation, and are capable of handling hot water HW obtained by heat exchange between the primary heat exchanger 48 and the secondary heat exchanger 50 for hot water supply. It is possible to pour hot water into the bathtub 14.

A fuel gas supply pipe 62 is connected to the burners 52 and 58, and fuel gas G is supplied thereto. A source gas solenoid valve 64 and a gas proportional valve 66 are installed in the fuel gas supply pipe 62, and a switching solenoid valve 68, a gas solenoid valve 70, and a switching solenoid valve 72 are installed on the burner 52 side. A gas solenoid valve 74 is installed. An air supply fan 76-1 is provided as an air supply means on the burner 52 side, and an air supply fan 76-2 is provided on the burner 58 side, and air necessary for burner combustion is supplied. Therefore, for hot water supply, hot water pouring, or reheating of bathtub water BW, the amount of gas burned by the burners 52 and 58 necessary for controlling the hot water supply temperature, hot water pouring temperature, and reheating temperature is controlled by the opening degree of the gas proportional valve 66, etc. be done.

The water supply W is supplied from the water supply pipe 80 to the secondary heat exchanger 50 , and after passing through the secondary heat exchanger 50 , it is guided to the primary heat exchanger 48 . The hot water HW after heat exchange in the heat exchangers 48 and 50 is guided to the hot water supply pipe 82. A bypass pipe 86 is provided between the water supply pipe 80 and the hot water supply pipe 82, and the water supply W can be mixed with the hot water HW. The bypass pipe 86 mixes the supplied water W with the hot water HW after heat exchange in order to improve responsiveness to the set temperature during hot water supply. The hot water HW is poured into the bathtub 14 through the circulation path 12 by a water injection pipe 88, which is an example of the water injection section 6 (FIG. 1). The water injection pipe 88 is used to fill the bathtub 14 with both hot water HW after heat exchange and water supply W before heat exchange.
The water supply pipe 80 is equipped with a water supply temperature sensor 90 and a water amount sensor 92, and the hot water supply pipe 82 is equipped with a hot water outlet temperature sensor 96, a water control valve 98, and a mixing temperature sensor 100. The bypass pipe 86 is equipped with a bypass solenoid valve 102 .

The feed water temperature sensor 90 detects the temperature of the feed water. The water amount sensor 92 detects the amount of water flowing into the water supply pipe 80 . A hot water temperature sensor 96 detects the hot water temperature after heat exchange. The bypass solenoid valve 102 controls the amount of water supplied W to be mixed with the hot water HW. The water control valve 98 is used to control the amount of water and hot water supplied. Mixture temperature sensor 100 detects the temperature of the mixture of hot water HW and feed water W.
The water injection pipe 88 is equipped with a metal injection solenoid valve 104, a metal injection amount sensor 106, and a check valve 108. The pouring electromagnetic valve 104 is used to adjust the amount of hot water poured into the bathtub 14. A pouring amount sensor 106 measures the pouring amount. The check valve 108 is a means for separating the water supply pipe 80 and the hot water supply pipe 82 from the bathtub water BW.

A drain receiver 110 is provided on the side of the secondary heat exchanger 50, and drain D generated by heat exchange is collected in the drain receiver 110. Drain D in the drain receiver 110 is led to a neutralizer 113 through a drain pipe 112 and neutralized, and then stored in the drain tank 10. Drain D from the drain tank 10 is led to the return pipe 12-1 of the circulation path 12 through the drain pipe 114. The drain pipe 114 is equipped with a check valve 116 . The check valve 116 is a means for separating the circulation path 12 and the drain pipe 114.

The circulation path 12 is equipped with temperature sensors 118 and 120, a two-way valve 122, a three-way valve 124, a circulation pump 18, and a bathtub water level sensor 24. The temperature sensor 118 detects the temperature of the bathtub water BW coming out of the bathtub 14 . Temperature sensor 120 detects the temperature of bathtub water BW entering bathtub 14. The two-way valve 122 is used to open and close the circulation path 12. The three-way valve 124 is used when drain D from the drain pipe 114 flows into the return pipe 12-1 of the circulation path 12. The circulation pump 18 is driven when reheating the bathtub water BW, pouring hot water HW into the bathtub 14, or discharging the drain D. The bathtub water level sensor 24 is used to detect the level of bathtub water BW in the bathtub 14.
The hot water reheating device 42 is equipped with a control section 128, and is equipped with a bathroom remote control device and a kitchen remote control device (not shown) as means for controlling and instructing operations.
In this hot water reheating device 42, the drain discharge section 4 is constituted by, for example, a drain pipe 114, a circulation path 12, and a bathtub 14, but the present invention is not limited thereto.

<Control unit 128>
FIG. 6 shows an example of the control unit 128. The control unit 128 includes a hot water supply control unit 130 each composed of a computer, a bathroom remote control control unit 132 installed in a bathroom remote control device, and a kitchen remote control control unit 134 installed in a kitchen remote control device.
The hot water supply control unit 130 includes a processor 136, a memory unit 138, a communication unit 140, and an input/output unit (I/O) 142. The processor 136 executes an OS (Operating System), a hot water reheating program, a drain discharge program, etc. stored in the memory unit 138. The memory unit 138 is composed of storage elements such as ROM (Read-Only Memory), RAM (Random-Access Memory), and EEPROM (Electrically Erasable Programmable Read-Only Memory). In addition to the drain discharge program, a bathtub data table 28 is stored as the bathtub database described above.

The communication unit 140 is controlled by the processor 136 and is used for data communication with the communication unit 166 of the kitchen remote control control unit 134 and the communication unit 150 of the bathroom remote control control unit 132.
The I/O 142 receives the outputs of the water flow switch 20, bathtub water level sensor 24, drain level sensor 40, pouring water amount sensor 106, drain timer 144, etc., the circulation pump 18, the water control valve 98, the pouring solenoid valve 104, and the water pouring solenoid valve 104. It is used to take out the control output to the one-way valve 122, three-way valve 124, etc.
The drain timer 144 is used to time a predetermined period of time, for example, 3 minutes, as a standby time when the drain D is drained.

Like the hot water supply control section 130, the bathroom remote control section 132 includes a processor 146, a memory section 148, a communication section 150, and an I/O 152. The processor 146 performs cooperative control with the hot water supply control unit 130, as well as starts and presents automatic operation, displays control information, and outputs an alert for drain discharge abnormality.
The I/O 152 is used to receive input from the automatic operation switch 154, turn on or off an LED (Light Emitting Diode) 156 as an indicator, display output from the liquid crystal display 158, and output audio from the speaker 160.

Like the hot water supply control section 130, the kitchen remote control control section 134 includes a processor 162, a memory section 164, a communication section 166, and an I/O 168. The processor 162 performs cooperative control with the hot water supply control unit 130, as well as starts and presents automatic operation, displays control information, and outputs an alert for drain discharge abnormality.
The I/O 168 is used to receive input from the automatic operation switch 170, turn on or off the LED 172 as an indicator, display output from the liquid crystal display 174, and output audio from the speaker 176.

<Drain D discharge treatment>
FIG. 7 shows a process for discharging the drain D of the hot water reheating device 42. Hot water HW after heat exchange is used for this wastewater treatment. In this processing procedure, the drain discharge timing is detected and the drain is discharged. It is determined whether the drain level DL is higher than or equal to the upper level Href (DL≧Href) (S200). This drain level DL may be detected by the drain level sensor 40. If this drain level DL is equal to or higher than the upper level Href (YES in S200), it is time to discharge the drain, so S201 to S204 are skipped and the process moves to S205 to proceed to the drain draining process. If the drain level DL is less than the upper level Href (NO in S200), the bathtub water level is monitored by the bathtub water level sensor 24 in order to detect the drain discharge timing by opening the bathtub tap 16 (S201). It is determined whether the bathtub water level has become less than the reference water level (bathtub water level < reference water level) by opening the bathtub faucet 16 and draining the bathtub water BW, etc. (S202). If the bathtub water level<the reference water level (YES in S202), the drain timer 144 starts timing (S203). The drain timer 144 times out after a certain period of time, for example, three minutes, which is sufficient to drain the remaining bathtub water BW. It is determined whether the drain timer 144 has timed out (S204). The process waits until 3 minutes have elapsed, and after the 3 minutes have elapsed, the circulation pump 18 is driven to check whether there is any remaining hot water in the bathtub 14 (S205). The presence or absence of the remaining hot water may be determined by determining whether or not the remaining hot water flows through the circulation path 12 based on the output of the water flow switch 20, which is an example of water flow detection means.

It is determined whether there is any remaining hot water in the bathtub 14 (S206), and if there is any remaining hot water in the bathtub 14 (NO in S206), the circulation pump 18 is stopped (S207), and S208 to S215 are skipped. , and drain D is not discharged.
If there is no bath water BW (remaining hot water) in the bathtub 14 (S206: YES), the circulation pump 18 is stopped (S208) and a drain discharge circuit is established (S209). The drain discharge circuit is a drain D path from the drain tank 10 to the bathtub 14 or from the drain tank 10 to the outside of the bathtub 14 when the bathtub plug 16 is opened.
A in FIG. 8 shows the amount of water at the initial water level, and B in FIG. 8 shows a state in which the bathtub 14 is empty. At the timing of S209, as shown in FIG. 8B, the bathtub 14, circulation path 12, etc. are in an empty state.
After the drain discharge circuit is established, the circulation pump 18 is driven (S210), and the drain D is discharged from the drain tank 10 into the bathtub 14 through the drain discharge circuit. While the circulation pump 18 is operating, it is determined whether the drain D has finished being discharged (S211). The determination of the end of draining may be made by measuring the time during which draining can be completed even if the drain D in the drain tank 10 is full, or by measuring the time at which the drain D can be finished by using the lower level detection electrode 40-2 of the drain tank 10 in FIG. It may also be possible to detect that the current level has fallen below the lower level Lref. If drain D has been discharged (YES in S211), the circulation pump 18 is stopped (S212), and the pouring circuit is established (S213). The hot water pouring circuit is a hot water supply path from the hot water supply pipe 82 to the bathtub 14 through the water filling pipe 88 and the circulation path 12. This hot water pouring circuit is established by opening the hot water pouring solenoid valve 104 of the water pouring pipe 88 and establishing a state in which hot water HW can be poured into the bathtub 14. From this hot water pouring circuit, a certain amount of hot water is poured into the bathtub 14 to also clean the circulation path 12, for example, a water amount W1 corresponding to the bathtub water level of 3 [cm] is poured (S214). 18 to discharge the residual water in the circulation path 12 (S215), and this process ends.
Note that if the bathtub stopper 16 is opened during the lapse of three minutes in S204, the bathtub 14 will be in an empty state as shown in A of FIG. During the lapse of three minutes in S204, if this state is considered to be the end of drainage and the bathtub stopper 16 is closed, the drainage will be incomplete. That is, as shown in the state of B in FIG. 9, the drain D and the poured water (S214) in an amount of water W1 corresponding to the bathtub water level of 3 [cm] remain in the bathtub 14 and the like.

<Fully automatic operation [1]>
FIG. 10 shows the processing procedure for fully automatic operation [1] of the hot water reheating device 42. The processing procedure of this automatic operation [1] is a process for acquiring water level information 32 (B in FIG. 3) of the bathtub 14 when the hot water reheating device 42 is installed.
In this processing procedure, it is necessary to turn on the automatic operation switch 154 or the automatic operation switch 170, and in order to execute data storage, turning on the automatic operation switch 154 or the automatic operation switch 170 is a condition. It is determined whether the automatic operation switch 154 or 170 is ON (S301), and if the automatic operation switch 154 or 170 is ON (YES at S301), a predetermined amount, for example, 10 [liters] of hot water is poured (S302). ).
The circulation pump 18 is driven to check whether there is any remaining hot water (S303). If there is hot water remaining (NO in S304), steps S307 to S317 are skipped, the circulation pump 18 is stopped (S305), and after draining, a re-execution instruction is output from the remote control device (S306), and this process is ended.
If there is no remaining hot water (YES in S304), the circulation pump 18 is stopped (S307), and after pouring a predetermined amount of hot water again to fill the circulation path 12 with water, the two-way valve 122 is closed, and the outgoing pipe 12 is filled with water. Pouring starts from -2 (S308).

Processes from S309 to S314 are performed during pouring. It is determined whether the initial water level has been detected by the bathtub water level sensor 24 (S309). If the initial water level is detected (YES in S309), the sensor value Lini and the water amount Vini are stored as the initial water level (S310).
At this timing, as shown in A of FIG. 8, the bathtub 14 is at the initial water level and the circulation path 12 and the like are filled with water. In other words, the amount of water Vini includes the amount of water inside the pipe.
It is determined whether the water level sensor value has reached Lini+a predetermined level, for example, 8 [cm] or more (water level sensor value≧Lini+8 [cm]) (S311).
If the water level sensor value≧Lini+8 [cm] (YES in S311), the sensor value (Lst=measured value−Lini) and water volume (Vst=measured value−Vini) are stored as the reference water level (S312).
Here, a water amount W1 corresponding to a water level of 3 [cm] in the bathtub 14 and a water amount W2 corresponding to a water level of 2 [cm] are calculated and stored.
The following methods can be considered for calculating W1 and W2.
Pattern 1: The standard height of the circulation port is 15 [cm]. Therefore, from the initial water amount Vini stored in S310,
W1=Vini/15×3...(3)
W2=Vini/15×2...(4)
shall be.
Pattern 2: The initial water level Lini+3 [cm] is detected before the reference water level Lst (initial water level Lini+8 [cm]) is detected in S311, and the note after the initial water level detection when the initial water level Lini+3 [cm] is reached. Let the amount of hot water be W1. The amount of water W2 is determined by the calculated W1.
W2=W1/3×2...(5)
shall be.
The calculation method is not limited to the above calculation method, and it is sufficient that the water amount W1 corresponds to the water level of 3 [cm] in each bathtub 14, and the water amount W2 corresponds to 2 [cm].
Pouring continues, and it is determined whether the water level sensor value is equal to or higher than the set water level (water level sensor value≧set water level) (S314). If the water level sensor value≧set water level (YES in S314), the water amount Vd per stage is stored as the set water level (S315).
After storing this water amount Vd, pouring of the hot water is stopped, the two-way valve is opened (S316), the circulation pump 18 is driven, and additional heating is performed until the set temperature is reached (S317), and this process is ended.

<Fully automatic operation [2]>
FIG. 11 shows the processing procedure for fully automatic operation [2] of the hot water reheating device 42. The processing procedure of automatic operation [2] is operation after data storage according to automatic operation [1] (FIG. 8).
In this processing procedure, it is determined whether the automatic operation switch 154 or 170 is ON (S401), and if the automatic operation switch 154 or 170 is ON (YES at S401), it is determined whether there was drain discharge last time ( S402). This is to confirm that the draining process shown in FIG. 7 has been recently performed on the bathtub 14, and that the processes after S208 have been executed. If no drain was discharged last time (NO in S402), S403 to S409 are skipped and the process moves to S410.
If drain was discharged last time (S402: YES), the presence or absence of remaining hot water is checked using the bathtub water level sensor 24 (S403).

If there is hot water remaining (NO in S404), it is determined that water was poured without going through the hot water reheating device 42 after draining, and S405 to S409 are skipped, and the process moves to S410.
If there is no remaining hot water (S404: YES), the state is shown in FIG. 9A or FIG. 9B, which is the final state of the discharge process in FIG. is poured (S405).
As a result, in the case of A in FIG. 9, the state is as shown in A in FIG. 12, and the initial water level Lini is not reached. Moreover, in the case of B in FIG. 9, the state becomes as shown in B in FIG. 12, and the water level exceeds the initial water level Lini.
The circulation pump 18 is driven (S406), and it is determined whether or not the water flow switch 20 is turned on (S407). If the water flow switch 20 is turned on (YES in S407), the state shown in FIG. 12B is reached. Either or both of a warning sound and a warning display is output as a drainage abnormality (S408), and this process is ended.
If the water flow switch 20 is not turned on (NO in S407), the circulation pump 18 is stopped (S409), water is poured to the set water level (S410), and the water is boiled to the set temperature (S411).
Note that the re-execution of pouring after draining may be performed together with an alert output and after the alert is canceled after draining.

<Effects of Example 1>
According to this first embodiment, the following effects can be obtained.
(1) Even if the bathtub plug 16 of the bathtub 14 is closed by mistake when drain D is discharged, an abnormality will be automatically determined from the water level after the initial pouring of water in the bathtub 14 the next time the hot water is filled, and an alert will be alerted to the abnormality. Notification can be made by output.
(2) This alert can be announced by voice or display from the bathroom remote control device or the kitchen remote control device, allowing the user to easily recognize abnormalities in drain discharge.

(3) If an abnormality in drain discharge is recognized, the bathtub tap 16 can be opened at that point to empty the bathtub 14.
(4) An abnormality in drain discharge can be determined by pouring the initial amount of hot water, and if it is discharged in the event of an abnormality, the drain D can be discharged outside the bathtub, and the bathtub 14 can be cleaned at the same time with the initial amount of hot water poured.
(5) If there is an abnormality in drain discharge, pouring will be stopped after an alert is output, thereby preventing wasted pouring.
(6) In Embodiment 1, after drain D is discharged, a certain amount of water is poured as cleaning water, so it is possible to improve the detection accuracy of discharge abnormality when there is little remaining drain D, and prevent the drain D from remaining. can do.
(7) When the volume of the bathtub is large, if a certain amount of hot water is poured, for example, 15 [liters], the water level will be about 1 [cm] or less. In a bathtub with a narrow area near the circulation opening, a fixed amount of hot water, for example 15 liters, is too large and the water level far exceeds the circulation opening. Since the amount of water to be judged is determined according to the amount of water, such inconvenience can be eliminated. For example, based on the area of the bathtub at the height near the circulation opening, the amount of water injected after draining is set as the amount of water W1 corresponding to a water level of 3 [cm], and the amount of water is less than the initial water amount by the amount of water W2 corresponding to a water level of 2 [cm]. Since hot water is poured, the accuracy of water level determination can be improved. In other words, water is poured in an amount equivalent to a water level of 3 cm after the drain is discharged, and the next time the water is automatically filled, the water is poured to a water level that is 2 cm lower than the position of the circulation port 22. If the port 22 is submerged in water, it may be determined that drain water remains.
(8) The water level in the bathtub can be measured by a water level sensor, and the water amount can be measured by the water flow sensor 92 or the pouring water sensor 106. If we assume these measurement errors and residual water in the pipes, the water level in the bathtub should be about 1 cm. . In this embodiment, the following patterns 1 and 2 can be assumed as an example of a method for calculating the amount of water.
In pattern 1, the standard height of the circulation port 22 is assumed to be 15 [cm], and when the initial water level is detected, the amount of water per 1 [cm] is calculated from "the amount of water injected so far/15". Thereby, the amount of water can be calculated as 2 [cm] = W2 and 3 [cm] = W1.
In pattern 2, between the detection of the initial water level and the detection of the reference water level (initial water level + 8 [cm]), the amount of water up to the initial water level + 3 [cm] is connected to the circulation port 22 through which water is drained when draining. It is detected by the bathtub water level sensor 24. The amount from this detected water level to a water level rise of 3 [cm] is defined as the amount of water injected after drain discharge W1, and two-thirds thereof is defined as the amount of water W2 that is reduced from the initial water amount. Both of Pattern 1 and Pattern 2 can improve the accuracy of determining whether the drain D remains.

<Drain D discharge treatment>
FIG. 13 shows a processing procedure for drain D discharge processing according to the second embodiment.
In the processing procedure of this second embodiment, similarly to the discharge processing of the first embodiment, detection of drain discharge timing and drain discharge are performed. It is determined whether the drain level DL is higher than or equal to the upper level Href (DL≧Href) (S500). This drain level DL may be detected by the drain level sensor 40. If this drain level DL is equal to or higher than the upper level Href (YES in S500), it is time to discharge the drain, so S501 to S504 are skipped and the process moves to S505 to proceed to the drain draining process. If the drain level DL is less than the upper level Href (NO in S500), the water level of the bathtub is monitored (S501) to detect the drain discharge timing by opening the bathtub tap 16, and the water level of the bathtub is determined to be less than the reference water level (S502). , If the water level of the bathtub is < the reference water level, start the drain timer 144 (S503), determine whether the drain timer 144 has timed up (S504), drive the circulation pump 18, check the remaining hot water (S505), and check the remaining water in the bathtub 14. After determining the amount of hot water (S506), if there is hot water remaining in the bathtub 14 (NO in S506), the circulation pump 18 is stopped (S507), steps S508 to S516 are skipped and the process ends, and the drain D is not discharged. .

If there is no bath water BW (remaining hot water) in the bathtub 14 (S506: YES), the circulation pump 18 is stopped (S508), and it is determined whether the drain level DL is less than the lower level Lref (DL<Lref) (S509). This drain level DL may be detected by the drain level sensor 40.
If DL<Lref (YES in S509), there is no drain D to be discharged, so S510 to S513 are skipped to perform normal pipe cleaning, and the process moves to S514. In this case, the amount of hot water poured in S515 may be a predetermined amount that can clean the circulation path 12, for example, 10 [liters].
If DL<Lref is not satisfied (NO in S509), a drain discharge circuit is established (S510), the circulation pump 18 is driven (S511), and drain D is discharged from the drain tank 10 into the bathtub 14 through the drain discharge circuit.
It is determined whether the drain level DL is less than the lower level Lref (DL<Lref) (S512).
If DL<Lref does not hold (NO in S512), drain D continues to be discharged. If DL<Lref (YES in S512), the circulation pump 18 is stopped (S513), and the pouring circuit is established (S514).
A certain amount of hot water is poured into the bathtub 14 from the hot water pouring circuit to clean the circulation path 12, for example, a water amount W1 corresponding to the bathtub water level of 3 [cm] is poured (S515), and then the circulation pump 18 is poured for a predetermined period of time. is driven to discharge the residual water in the circulation path 12 (S516), and this process ends.

<Effects of Example 2>
According to this second embodiment, the following effects can be obtained.
(1) The drain discharge process can be omitted when no drain is accumulated, and the drain discharge process can be performed only when the drain D is accumulated, making it possible to improve the efficiency of the process.
(2) The drain level DL of the drain tank 10 can be monitored and the drain D stored in the drain tank 10 can be reliably discharged.
(3) Since the drain level DL of the drain tank 10 is monitored and the circulation pump 18 is driven only until the drain D stored in the drain tank 10 becomes less than the lower level Lref which is the reference level, the drain level DL is monitored. Pump drive time can be minimized.

FIG. 14 shows a hot water reheating device 42 according to the third embodiment. This third embodiment is a configuration of the hot water reheating device 42 of the first embodiment at a concrete implementation level.
In this third embodiment, the combustion chambers 44-1, 44-2 and supply air fans 76-1, 76-2 of the first embodiment are configured into a single combustion chamber 44 and a single supply air fan 76, making it more compact. ing.
An exhaust port 178 is provided on the burner 52 side, and an exhaust port 180 is provided on the burner 58 side to ensure ventilation within the device.
Since the other configurations are the same as those in FIG. 5, the same parts are denoted by the same reference numerals, and the description of each member will be omitted.

<Effects of Example 3>
According to this third embodiment, the same effects as those of the previously described embodiment, first embodiment, and second embodiment can be obtained, and in addition to making the device more compact, it is possible to prevent the drain D from remaining in the bathtub 14. The inside of the bathtub 14 can be cleaned in the hot water reheating device that can be operated fully automatically.

[Other embodiments]
(1) In the above embodiments, the first embodiment and the second embodiment are described separately regarding the discharge of the drain D, but a configuration including both of these may be used.
(2) Although the above embodiment describes the hot water supply and reheating functions, the present invention may be applied to a hot water supply, reheating, or space heating device with a heating function, or may be applied to a heat medium heating device. Good too.
(3) In the drain discharge process (FIG. 7), pouring of molten metal is illustrated in S214, but pouring of water may be used in place of pouring of molten metal without burner combustion and heat exchange.

As described above, the most preferred embodiments of the drain discharge method, drain discharge device, and hot water supply device have been described. The present invention is not limited to the above description. Various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the detailed description. It goes without saying that such modifications and changes are included within the scope of the present invention.

According to the present invention, even if the bathtub stopper is closed by mistake when draining drain D into the bathtub, it is possible to determine whether drain D is draining abnormally by the water injection operation, and the abnormality is notified by an alert, so that the residual drain is inconvenient. This is beneficial because it can be avoided.

D Drain W Water supply HW Hot water BW Bathtub water 2 Drain discharge device 4 Drain discharge section 6 Water injection section 8 Alert output section 10 Drain tank 12 Circulation path 14 Bathtub 16 Bathtub tap 18 Circulation pump 20 Water flow switch 22 Circulation port 24 Bathtub water level sensor 26 Bathtub Bottom surface 28 Bathtub data table 30 Bathtub information 32 Water level information 32-1 Initial water level information 32-2 Standard water level information 32-3 Set water level information 34 Introduction port 36 Discharge port 38 Overflow port 40 Drain level sensor 42 Hot water reheating device 44 Combustion chamber 44-1 Combustion chamber for hot water supply 44-2 Combustion chamber for reheating 48 Primary heat exchanger 50 Secondary heat exchanger 52 Burner 54 Combustion exhaust 56 Heat exchanger 58 Burner 60 Combustion exhaust 62 Fuel gas supply pipe 64 Original gas solenoid valve 66 Gas proportional valve 68 Switching solenoid valve 70 Gas solenoid valve 72 Switching solenoid valve 74 Gas solenoid valve 76-1, 76-2 Air supply fan 80 Water supply pipe 82 Hot water supply pipe 86 Bypass pipe 88 Water injection pipe 90 Water supply temperature sensor 92 Water amount sensor 96 Hot water temperature sensor 98 Water control valve 100 Mixing temperature sensor 102 Bypass solenoid valve 104 Solenoid valve for pouring hot water 106 Pouring amount sensor 108 Check valve 110 Drain receiver 112, 114 Drain pipe 113 Neutralizer 116 Check valve 118, 120 Temperature sensor 122 Two-way valve 124 Three-way valve 128 Control section 130 Hot water supply control section 132 Bathroom remote control section 134 Kitchen remote control control section 136, 146, 162 Processor 138, 148, 164 Memory section 140, 150, 166 Communication section 142, 152, 168 Input/output Part 154, 170 Automatic operation switch 156, 172 LED
158, 174 LCD display 160, 176 Speaker 178, 180 Exhaust port

By the way, when drain from a drain tank is discharged through a bathtub, the bathtub is simply used as a drainage path, and the drain does not mix into the bathtub water. For this reason, when draining the drain from the drain tank through the circulation path into the bathtub and draining it from the bathtub's drain port into the drain pan, after draining the drain, by supplying water to the bathtub through the circulation path, the drain can be drained from the circulation path piping and the bathtub. Measures are being taken to ensure that no residue remains.
This type of drainage is based on the assumption that the bathtub stopper is open, and if the bathtub stopper is closed by mistake, the draining water may remain in the circulation path or inside the bathtub, causing it to mix with the bathtub water. There is a problem with this. Even if a predetermined amount of water or hot water is supplied for cleaning, if the valve is closed, drain cannot be discharged from the bathtub. If the user closes the bathtub valve and switches to automatic hot water supply without noticing this drain discharge, there is a risk that this kind of drain may remain.If the drain gets mixed into the bath water, the drain is colorless and transparent, so the bathtub There is a problem in that it is not possible to determine whether or not condensate is mixed in the water.
By the way, the inventor of the present application poured a certain amount of water when discharging the drain into the bathtub, also to clean the pipe through which the drain passed, and when the next automatic hot water filling was performed, the amount of water poured in was smaller than the initial water level. We have obtained knowledge that it is possible to confirm whether there is residual drain by checking whether or not it exceeds the circulation port .

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to determine whether drain remains by pouring water after draining, and to prompt the user to drain the drain .

In order to achieve the above object, according to one aspect of the water filling method of the present invention, there is provided a water filling method for a bathtub used for discharging drain from a drain tank that collects drain generated in a heat exchanger , the method comprising: At a timing when the drain in the drain tank exceeds a reference level and no water flow is generated during bathtub water circulation driven by a circulation pump provided in a circulation path connected to the bathtub , the drain is transferred from the drain tank to the bathtub. a step of draining, a step of checking whether or not the drain has been drained, and if the drain has been drained, pouring water into the bathtub with the bathtub stopper closed , and after pouring a certain amount of water into the bathtub, a step of determining whether or not a part or all of the circulation port of the bathtub is submerged in water based on the presence or absence of water flow due to circulation of bathtub water in the circulation path by driving the circulation pump ; If part or all of the ring opening is not submerged in water, the method includes the step of continuing to pour water into the bathtub to a set water level and boiling the bathtub to a set temperature.
In this water injection method , further, after discharging the drain from the drain tank into the bathtub, a water injection circuit to the circulation path is established to inject a certain amount of water into the circulation path, and the circulation pump is turned on for a predetermined period of time. The method may include a step of driving the water to discharge residual water in the circulation path into the bathtub .
In this water filling method, the step of discharging the drain into the bathtub further includes the step of detecting the water level of the drain in the drain tank, and when the water level of the drain is at a lower level or higher, the drain is transferred from the drain tank to the bathtub. establishing a condensate discharge circuit connected to the bathtub to begin discharging the condensate to the bathtub, or to stop discharging the condensate if the condensate is below the lower level; and stopping discharge of the drain when the water level of the drain becomes lower than the lower level .

In order to achieve the above object, according to one aspect of the water injection system of the present invention, there is provided a water injection system for a bathtub used for discharging drain from a drain tank that collects drain generated in a heat exchanger , the system comprising: a bathtub; a level sensor that detects the level of drain stored in the drain tank; a drain discharge section that discharges the drain from the drain tank into the bathtub; a circulation path used for circulation and draining drain into the bathtub; a circulation pump provided in the circulation path for circulating the bathtub water in the circulation path; and a water injection unit for injecting water into the bathtub through the circulation path. , a heat exchange means for exchanging heat of combustion of fuel gas to water supply or the bathtub water; and a drain timing of the bathtub, or a drain of the drain tank exceeding a reference level and a water flow generated by pump circulation of the bathtub water; After the drain is discharged from the drain tank into the bathtub at a timing when the drain is not discharged, check whether or not the drain has been discharged, and if the drain has been discharged, water is poured into the bathtub with the bathtub stopper closed. After pouring a certain amount of water into the bathtub, it is determined whether a part or all of the circulation port of the bathtub is submerged in water based on the presence or absence of water flow due to circulation of bathwater in the circulation path by driving the circulation pump. , a control unit that continues to pour water into the bathtub to a set water level and boils it to a set temperature if a part or all of the circulation port is not submerged by the certain amount of water being poured;
including.
In this water injection system, the control unit further includes, after discharging the drain from the drain tank into the bathtub, establishing a water injection circuit to the circulation path to inject a certain amount of water into the circulation path; The pump may be driven for a predetermined period of time to discharge residual water in the circulation path into the bathtub .
In this water injection system , when the drain is discharged into the bathtub, the control section establishes the drain discharge section when the water level of the drain is at a lower level or higher based on a detection value of the level sensor, and start discharging the condensate, or stop discharging the condensate when the condensate is below the lower level, and further, when the detected value of the level sensor becomes less than the lower level due to the drain discharge. Discharge of the drain may be stopped immediately .

Claims (7)

A water injection method that also uses drain discharge from a drain tank that collects drain generated during heat exchange,
Discharging the drain from the drain tank into the bathtub at the timing of draining the bathtub, or at the timing when the drain of the drain tank exceeds a reference level and no water flow is generated due to pump circulation of the bathtub water;
After discharging the drain, pouring water into the bathtub;
After pouring a certain amount of water into the bathtub, determining whether part or all of the circulation port of the bathtub is submerged in water;
If part or all of the circulation port of the bathtub is submerged due to the certain amount of water being poured into the bathtub, continuing to pour water into the bathtub to a set water level and boiling the bathtub to a set temperature;
Water injection methods, including: If part or all of the circulation port of the bathtub is not submerged in water, the circulation pump is driven for a predetermined period of time to discharge residual water in the circulation path, and then water is poured to the set water level in the bathtub to boil it to the set temperature. The water injection method according to claim 1, comprising: If part or all of the circulation port of the bathtub is submerged due to pouring a certain amount of water into the bathtub when draining the drain, output alert information and allow water to be poured into the bathtub after draining the bathtub. The water injection method according to claim 1, comprising the step of. A water injection system that also uses drain discharge from a drain tank that collects drain generated during heat exchange,
bathtub and
a level sensor that detects the level of drain stored in the drain tank;
a drain discharge part that discharges the drain from the drain tank into the bathtub;
a circulation path used for pouring water into the bathtub, circulating bathwater in the bathtub, and discharging drain into the bathtub;
a circulation pump that circulates the bath water in the circulation path;
a water injection unit that injects water into the bathtub through the circulation path;
heat exchange means for exchanging combustion heat of the fuel gas to the water injection or the bath water;
The drain is discharged from the drain tank into the bathtub at the timing of draining the bathtub, or at the timing when the drain of the drain tank exceeds a reference level and no water flow is generated during pump circulation of the bathtub water, and after draining the drain. , pour water into the bathtub, and after pouring a certain amount of water into the bathtub, determine whether a part or all of the circulation opening of the bathtub is submerged in water; a control unit that continues to pour water into the bathtub up to a set water level and boils it to a set temperature when the bathtub is partially or completely submerged;
Including water injection system. If part or all of the circulation port of the bathtub is not submerged in water, the control unit drives the circulation pump for a predetermined period of time to drain residual water in the circulation path, and then fills the bathtub with water up to a set water level. The water injection system according to claim 4, wherein the water is boiled to a set temperature. The control unit outputs alert information when a part or all of the circulation port of the bathtub is submerged due to pouring a certain amount of water into the bathtub when discharging the drain, and outputs alert information, and after draining the bathtub, the control unit outputs alert information. 5. The water injection system according to claim 4, which allows water injection into the water. A water heater comprising the water injection system according to claim 4, claim 5, or claim 6.

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