Drain discharge method, drain discharge device, and hot water supply device

Abstract

To determine whether drain remains by pouring water after drain is discharged, to encourage a user to discharge drain.SOLUTION: A drain discharge method for discharging drain (D) stored in a drain tank (10) through a bathtub (14), when bathtub water is being discharged from the bathtub, or when the drain in the drain tank exceeds a reference level and there is no water flow from the pump circulation of the bathtub water, discharges the drain from the drain tank into the bathtub and stops the discharge of the drain from the drain tank, and after a water volume that does not submerge a circulation port partially or entirely into the bathtub is filled, when there is a water flow from the pump circulation, outputs an alert or stops the filling of water into the bathtub.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a technique for discharging drainage generated in a heat exchanger when, for example, the combustion heat of fuel gas is exchanged with feedwater or the like. [Background technology]

[0002] When the heat of combustion of fuel gas is exchanged with water supply, drainage occurs in the heat exchanger, but the generation of drainage is particularly noticeable in high-efficiency water heaters equipped with a secondary heat exchanger that recovers the latent heat of combustion. After being neutralized in a neutralizer, this drainage is collected in a drain tank and discharged through the bathtub when the bathtub stopper is opened. Regarding drainage, it is known to dilute or neutralize the drain in the drain tank and then drain it through a bathtub (for example, Patent Document 1).It is also known that the drain in the drain tank is drained through a reheating pipe at a predetermined drain timing (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-265228 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-270798 Summary of the Invention [Problem to be solved by the invention]

[0004] When drainage from the drain tank is discharged through the bathtub, the bathtub is simply used as a drainage path and the drainage does not get mixed into the bathtub water. For this reason, when drainage from the drain tank is discharged into the bathtub through the circulation path and then discharged into the drain pan from the bathtub drain outlet, water is supplied to the bathtub through the circulation path after the drainage is discharged, so that drainage does not remain in the piping of the circulation path or the bathtub. This drain discharge is based on the premise that the bathtub stopper is open. If the bathtub stopper is accidentally closed, the drain being discharged will remain in the circulation path or bathtub, causing the problem of the drain being mixed with the bathtub water. Even if the specified amount of water and hot water for cleaning is supplied, the drain cannot be discharged from the bathtub if the stopper is closed. If the user does not notice that the drain is being discharged and closes the bathtub stopper and switches to automatic hot water supply, there is a risk that this drain will remain. Furthermore, if the drain mixes with the bathtub water, there is the problem that it is impossible to determine whether the drain has mixed with the bathtub water because the drain is colorless and transparent. The inventors of the present application have discovered that when draining into a bathtub, a fixed amount of water is poured in to also clean the pipes through which the drain has passed, and that the next time the bath is automatically filled, the amount of water poured in that is less than the initial water level can be checked to see if the water level exceeds the circulation port. However, based on this knowledge, they have discovered that when a fixed amount of water is poured in, the water level varies depending on the volume and shape of the bathtub, so the judgment results vary and it may not be possible to check whether drain remains.

[0005] In view of the above, an object of the present invention is to determine whether drainage remains by pouring water after drainage, and to prompt the user to drain the drainage. In view of the above-mentioned problems, another object of the present invention is to improve drain discharge accuracy and pour water without being affected by the volume of the bathtub or the shape of the interior of the bathtub by determining the remaining amount of drain by submerging part or all of the circulation port when a certain amount of water is poured. [Means for solving the problem]

[0006] In order to achieve the above object, according to one aspect of the drain discharge method of the present invention, Occurring in the water heater A drainage method for draining drain stored in a drain tank through a bathtub, wherein the method comprises the steps of: when bath water is being drained from the bathtub; or when the drain in the drain tank exceeds a reference level and The circulation pump is driven to introduce water into the circulation path connected to the bathtub. Bathtub water flowsa step of discharging the drain from the drain tank into a bathtub when the drain is not in the drain tank; and after completing the discharge of the drain from the drain tank and pouring water into the bathtub in an amount that does not cause a part or all of the circulation port to be submerged, The circulation pump is driven to cause the bath water to flow into the circulation path connected to the bathtub. When force and

[0007] In order to achieve the above object, according to one aspect of the drain discharge device of the present invention, Occurring in the water heater A drain discharge device that discharges drain stored in a drain tank through a bathtub, the drain discharge device comprising: a level sensor that detects the level of the drain stored in the drain tank; a drain discharge path that discharges the drain from the drain tank into the bathtub; a circulation path and a circulation pump that circulate bathwater in the bathtub; and a pump that detects when bathwater is being discharged from the bathtub or when the drain in the drain tank exceeds a reference level and , the circulation pump is driven to Bathtub water flows When the drain tank is not in the drained state, the drain is discharged from the drain tank into the bathtub, the drain is discharged from the drain tank, and after the drain is discharged from the drain tank, a quantity of water is poured into the bathtub so that the circulation port is not partially or entirely submerged, The circulation pump is driven to cause the bath water to flow into the circulation path connected to the bathtub. When force and a control unit.

[0008] In order to achieve the above object, one aspect of the hot water supply apparatus of the present invention is a hot water supply apparatus that discharges drain stored in a drain tank through a bathtub, the hot water supply apparatus including the drain discharge device. [Effects of the Invention]

[0009] According to the present invention, one of the following effects can be obtained. (1) By pouring water after draining, it is possible to determine whether drain remains, and by notifying the user or stopping the water pouring, it is possible to prevent drain from remaining and pour water. (2) If the bathtub valve is closed, the user can open the bathtub valve in response to the alert output, which will allow the drain to be drained from the bathtub, which has already filled with a certain amount of water, and the bathtub can be filled with water that does not contain drain. (3) The drainage remaining in the bathtub is diluted by the initial water filling, so by opening the bathtub plug, the drainage can be discharged and the bathtub can be cleaned, and water that does not contain drainage can be filled into the bathtub. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing a drain discharge device according to an embodiment; [Figure 2] 10 is a flowchart showing a drain discharge process. [Figure 3] 1A is a diagram showing the bathtub water level setting according to the first embodiment, and FIG. 1B is a diagram showing a bathtub data table. [Figure 4] FIG. 1A is a front view showing the drain tank, and FIG. 1B is a side view showing the drain tank. [Figure 5] 1 is a diagram showing a hot water reheating device according to a first embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of a control unit of a hot water reheating device. [Figure 7] 10 is a flowchart showing a first procedure for drainage discharge. [Figure 8] A shows the initial water injection operation, and B shows the state before water injection. [Figure 9] A shows the state just before water is poured in, and B shows the remaining water in the bathtub. [Figure 10] 10 is a flowchart showing a first processing procedure for fully automatic driving. [Figure 11] 10 is a flowchart showing a second processing procedure for fully automatic driving. [Figure 12] A shows a normal drainage state, and B shows an abnormal drainage state. [Figure 13] 10 is a flowchart showing a procedure for drainage discharge according to the second embodiment. [Figure 14] FIG. 10 is a diagram showing a hot water reheating device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] [One embodiment] Fig. 1 shows a drain discharge device in a water injection system according to one 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.

[0012] The drain discharge unit 4 discharges the drain either when the bathtub 14 is drained by opening the bathtub stopper 16, or when it is confirmed that the drain D exceeds a reference level Dref, which is an example of the drain tank 10, and that no water flow is occurring when the bathtub water BW is circulated by the circulation pump 18. The presence or absence of a water flow is detected by a water flow switch 20, which is an example of a water flow detection means. After drain D is discharged, water injection unit 6 injects a certain amount of water. This certain amount of water is injected into bathtub 14 when it is empty and bathtub stopper 16 is closed, and serves to clean the drain discharge circuit, which will be described later. Even if the initial water injection is an amount of water less than the amount that would partially or completely submerge circulation port 22, the amount of water that will partially or completely submerge circulation port 22 after the certain amount of water is added is the amount of water that will partially or completely submerge circulation port 22. This water injection may be either water supplied before heating or warm water after heating. If the circulation port 22 is partially or completely 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 by the circulation of the bathtub water BW by the circulation pump 18, the alert output unit 8 outputs alert information indicating that drain D remains in the bathtub 14. The presence or absence of a water flow can be confirmed by checking the output of the water flow switch 20.

[0013] <Drain discharge process> 2 shows a process for drain discharge and detecting discharge abnormalities according to one embodiment. This process is an example of a drain discharge method in which drain D generated by heat exchange is stored in drain tank 10 and discharged from bathtub 14 through circulation path 12. The process includes draining drain D, determining whether to discharge drain D, pouring water, determining the water level in bathtub 14, and outputting alert information. The system determines whether it is the first or second drain timing for draining the drain D (S11). The first drain timing is when the bathtub 14 is drained after the bathtub stopper 16 is opened. The second drain timing is when it is confirmed that the drain D exceeds the reference level Dref in the drain tank 10 and that no water flow is occurring due to the pumped circulation of the bathtub water BW. This timing occurs, for example, when the drain D exceeds the upper level Href (Figures 4 and 5) of the reference level Dref.

[0014] 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, the drain discharge is performed by establishing a drain discharge circuit from the drain tank 10 through the circulation path 12 to the circulation port 22. The drain discharge circuit is a discharge path for the drain D 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 stopper 16 is opened. It is determined whether drain D has been completely discharged (S14), and if drain D has been completely discharged from the drain tank 10 (YES in S14), a certain amount of water, for example, a volume W1 equivalent to the bathtub water level of 3 cm, is poured from the water injection unit 6 to clean the drain discharge circuit including the circulation path 12 (S15). This completes drain discharge.

[0015] When pouring water after draining, a certain amount of water is initially poured into bathtub 14 from water pouring section 6 (S16). This initial amount of water is less than the amount of water that would submerge part or all of circulation port 22 by an amount W2 equivalent to, for example, 2 cm of the bathtub water level. During this pouring, bathtub stopper 16 is in the closed position.

[0016] It is determined whether the circulation port 22 is partially or completely submerged by this water injection (S17). This determination may be made, for example, by checking whether or not there is a water flow caused by the circulation of the bathtub water BW by the circulation pump 18. If circulation port 22 is not partially or completely submerged (NO in S17), drain D has been discharged from bathtub 14, and therefore no alert information is output (S18). If circulation port 22 is partially or completely submerged (YES in S17), an alert is output indicating that drain D remains in bathtub 14, or an alert indicating that water pouring has been stopped (S19). This alert can prompt the user to open bathtub stopper 16, i.e., to drain the bathtub.

[0017] <Effects of the embodiment> According to this embodiment, the following effects can be obtained. (1) When the water is next poured in, i.e., when the tub is filled with hot water, an alarm will sound to let you know if there is any drainage remaining from the previous drainage. (2) If there is an alarm indicating that water supply has stopped or an alarm indicating that drainage remains, simply drain the bathtub at that time, and drainage can be prevented from remaining. [Example]

[0018] <Bathtub water level setting> Fig. 3A shows the water level setting of the bathtub according to Example 1. 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 of the bottom of the bathtub 14. The height of this 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.

[0019] In the bathtub 14, an initial water level Lini, a reference water level Lst, and a plurality of set water levels Ln, for example, L1, L2, L3, . . . L11, are set at height intervals 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 a water level at which the return pipe 12-1 of the circulation path 12 is submerged. The reference water level Lst is set to a certain height, for example, about 8 cm, above the initial water level Lini. The set water level L1 is set at a certain height, for example, about 3 cm, above the reference water level Lst, and each set water level L1, L2, L3, ... L11 has a certain width in the vertical direction, for example, about 3 cm. The bathtub water level can be selected from the set water levels L1, L2, L3, ... L11.

[0020] The height from the bathtub bottom 26 to the set water level L1 is Set water level L1 height = 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) is.

[0021] If the resolution of the bathtub water level sensor 24 is 1 bit = 0.2125 cm, the height of each of the set water levels L1 to L11 is 3 cm, so 14 bits = 2.975 cm. The initial water volume from the bathtub bottom surface 26, including the water volume in the piping, to the initial water level Lini is Vini, the standard water volume from the initial water level Lini to the standard water level Lst is Vst, and the water volume from the standard water level Lst to the set water level L1 (= Ld) is Vd. These water volumes vary depending on the piping and bathtub 14.

[0022] <Bathtub Data Table 28> 3B shows the bathtub data table 28. 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. Bathtub information 30 stores information such as the installation status and size of bathtub 14.

[0023] The initial water level information 32-1 stores the water volume Vini from the bathtub bottom 26 to the initial water level Lini, including the water volume in the pipes. The water volume Vini is the measurement value of the bathtub water level sensor 24. The reference water level information 32-2 stores the reference water volume Vst from the initial water level Lini to the reference water level Lst. This reference water volume Vst is the measurement value of the bathtub water level sensor 24. The set water level information 32-3 stores the water volume Vd, which is the unit water volume for each set water level from the base water level Lst to the set water level L11. This information is used to control the fully automatic hot water supply, including drain discharge.

[0024] <Drain tank 10> Fig. 4A shows a vertical cross section of the drain tank 10, and Fig. 4B shows a cross section taken along line IVB-IVB of Fig. 4A. In this first embodiment, an upper level Href and a lower level Lref are set as the reference level Dref described above. The drain tank 10 is equipped with an inlet port 34, a discharge port 36, an overflow port 38, and a drain level sensor 40. Neutralized drain D is introduced into the drain tank 10 from the inlet port 34, where it is stored, and then discharged from the discharge port 36. When the drain D exceeds an upper limit level (overflow level) U, it is discharged from the overflow port 38 to the outside of the drain tank 10. The drain level sensor 40 is a sensor that detects the water level of drain D accumulated in the drain tank 10. The drain level sensor 40 is equipped with 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 of the drain D. In the drain tank 10, the common electrode 40-1 and the lower level detection electrode 40-2 detect a lower level Lref of the drain D, and the common electrode 40-1 and the upper level detection electrode 40-3 detect an upper level Href of the drain D. The upper level detection electrode 40-4 detects an upper level U that is higher than the upper level Href, and this upper level U is, for example, an overflow level.

[0025] <Hot water reheating device 42> 5 shows a hot water reheating device 42 according to a first embodiment of the water injection system equipped with the drain discharge device 2. This hot water reheating device 42 is an example of a hot water supply device. This hot water reheating device 42 has a hot water supply function for supplying hot water to places other than the bathtub 14, a hot water supply function for supplying hot water to the bathtub 14, and a function for reheating bathwater BW.

[0026] This hot water reheating device 42 is provided with a hot water combustion chamber 44-1 and a reheating combustion chamber 44-2. The hot water combustion chamber 44-1 is provided with a primary heat exchanger 48 and a secondary heat exchanger 50. The primary heat exchanger 48 exchanges 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 exchanges mainly latent heat of the combustion exhaust gas 54 that has passed through the primary heat exchanger 48 with the feed water W. The reheating combustion chamber 44-2 is equipped with a heat exchanger 56. The heat exchanger 56 exchanges sensible heat from the combustion exhaust 60 obtained by the combustion of the burner 58 with the bath water BW. The heat exchangers 48, 50, and 56 can be operated in either bidirectional or standalone mode, and the hot water HW obtained by heat exchange in the hot water supply primary heat exchanger 48 and secondary heat exchanger 50 can be used to supply hot water HW to the bathtub 14.

[0027] A fuel gas supply pipe 62 is connected to burners 52, 58, and fuel gas G is supplied through it. A main gas solenoid valve 64 and a gas proportional valve 66 are installed in fuel gas supply pipe 62, while a switching solenoid valve 68, gas solenoid valve 70, and switching solenoid valve 72 are installed on the burner 52 side, and a gas solenoid valve 74 is installed on the burner 58 side. An air supply fan 76-1 is installed on the burner 52 side as an air supply means, and an air supply fan 76-2 is installed on the burner 58 side, and these supply the air necessary for burner combustion. Therefore, for hot water supply, hot water pouring, or reheating of bathwater BW, the amount of gas combustion in burners 52, 58, which is necessary to control the hot water supply temperature, hot water pouring temperature, and reheating temperature, etc., is controlled by the opening of gas proportional valve 66, etc.

[0028] Supply water W is supplied from a water supply pipe 80 to secondary heat exchanger 50, and after passing through this secondary heat exchanger 50, is guided to primary heat exchanger 48. Hot water HW after heat exchange in heat exchangers 48, 50 is guided to hot water supply pipe 82. A bypass pipe 86 is provided between water supply pipe 80 and hot water supply pipe 82, allowing supply water W to be mixed with hot water HW. Bypass pipe 86 mixes supply water W with hot water HW after heat exchange to improve responsiveness to the set temperature when supplying hot water. Hot water HW is injected into bathtub 14 through circulation path 12 by water injection pipe 88, which is an example of water injection unit 6 (Figure 1). Water injection pipe 88 is used to inject both hot water HW after heat exchange and supply water W before heat exchange into bathtub 14. The water supply pipe 80 is equipped with a water supply temperature sensor 90 and a water volume sensor 92, and the hot water supply pipe 82 is equipped with an outlet hot water temperature sensor 96, a water control valve 98, and a mixed water temperature sensor 100. The bypass pipe 86 is equipped with a bypass solenoid valve 102.

[0029] The water supply temperature sensor 90 detects the water supply temperature. The water volume sensor 92 detects the volume of water supply flowing through the water supply pipe 80. The outlet hot water temperature sensor 96 detects the hot water temperature after heat exchange. The bypass solenoid valve 102 controls the volume of water supply W to be mixed with the hot water HW. The water control valve 98 is used to control the volume of water supply and hot water supply. The mixed temperature sensor 100 detects the temperature of the mixed water of the hot water HW and the water supply W. The water supply pipe 88 is equipped with a water supply solenoid valve 104, a water supply amount sensor 106, and a check valve 108. The water supply solenoid valve 104 is used to adjust the amount of water supplied to the bathtub 14. The water supply amount sensor 106 measures the amount of water supplied. The check valve 108 is a means for isolating the water supply pipe 80 and the hot water supply pipe 82 from the bathwater BW.

[0030] A drain receiver 110 is provided on the secondary heat exchanger 50 side, and drain D generated by heat exchange is collected in this drain receiver 110. The drain D in the drain receiver 110 is led through a drain pipe 112 to a neutralizer 113 where it is neutralized and then stored in the drain tank 10. The drain D in the drain tank 10 is led through a drain pipe 114 to the return pipe 12-1 of the circulation path 12. A check valve 116 is provided in the drain pipe 114. The check valve 116 is a means for isolating the circulation path 12 from the drain pipe 114.

[0031] The circulation path 12 is equipped with temperature sensors 118, 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 leaving the bathtub 14. The temperature sensor 120 detects the temperature of the bathtub water BW entering the bathtub 14. The two-way valve 122 is used to open and close the circulation path 12. The three-way valve 124 is used to flow drain D from the drain pipe 114 into the return pipe 12-1 of the circulation path 12. The circulation pump 18 is operated to reheat the bathtub water BW, to pour hot water HW into the bathtub 14, or to discharge drain D. The bathtub water level sensor 24 is used to detect the level of the bathtub water BW in the bathtub 14. This hot water reheating device 42 is provided with a control unit 128, and is provided with a bathroom remote control device and a kitchen remote control device (not shown) as means for controlling and instructing operation. In this hot water reheating device 42, the drain discharge section 4 is composed of a drain pipe 114, a circulation path 12, and a bathtub 14, for example, but is not limited to this.

[0032] <Control unit 128> 6 shows an example of control unit 128. This control unit 128 includes a hot water supply control unit 130, each of which is configured by a computer, a bathroom remote control control unit 132 installed in the bathroom remote control device, and a kitchen remote control control unit 134 installed in the kitchen remote control device. The hot water supply control unit 130 is equipped with a processor 136, a memory unit 138, a communication unit 140, and an input / output unit (I / O) 142. The processor 136 executes the OS (Operating System), hot water reheating program, drain discharge program, etc. stored in the memory unit 138. The memory unit 138 is composed of storage elements such as a ROM (Read-Only Memory), a RAM (Random-Access Memory), and an EEPROM (Electrically Erasable Programmable Read-Only Memory), and the ROM or EEPROM stores the OS, hot water reheating program, drain discharge program, and also the bathtub data table 28 as the bathtub database described above.

[0033] 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 unit 134 and the communication unit 150 of the bathroom remote control unit 132. I / O 142 is used to take in outputs from the water flow switch 20, bathtub water level sensor 24, drain level sensor 40, hot water volume sensor 106, drain timer 144, etc., and to take out control outputs to the circulation pump 18, water control valve 98, hot water supply solenoid valve 104, two-way valve 122, three-way valve 124, etc. The drain timer 144 is used to measure a certain time, for example, three minutes, as a standby time when the drain D is drained.

[0034] Similar to the hot water supply control unit 130, the bathroom remote control unit 132 is equipped with a processor 146, a memory unit 148, a communication unit 150, and an I / O unit 152. The processor 146 controls the connection with the hot water supply control unit 130, starts and indicates automatic operation, displays control information, and issues alerts for drain discharge abnormalities. The I / O 152 is used to take in input from an automatic operation switch 154 , turn on or off an LED (Light Emitting Diode) 156 as an indicator, output display information from a liquid crystal display 158 , and take out audio output from a speaker 160 .

[0035] Like the hot water supply control unit 130, the kitchen remote control unit 134 is equipped with a processor 162, a memory unit 164, a communication unit 166, and an I / O 168. The processor 162 controls the link with the hot water supply control unit 130, starts and indicates automatic operation, displays control information, and outputs alerts for drain discharge abnormalities. The I / O 168 is used to take in input from an automatic operation switch 170 , turn on or off an LED 172 as an indicator, output display data from a liquid crystal display 174 , and take out audio output data from a speaker 176 .

[0036] <Drain D discharge treatment> FIG. 7 shows the drain D discharge process of the hot water reheating device 42. This drain process uses hot water HW after heat exchange. This process involves detecting the drain discharge timing and drain discharge. A determination is made (S200) as to whether the drain level DL is equal to or higher than the upper level Href (DL≧Href). This drain level DL can 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 the process skips S201 to S204 and proceeds to S205, where the drain discharge process begins. If the drain level DL is lower than the upper level Href (NO in S200), the bathtub water level is monitored by the bathtub water level sensor 24 to detect the timing to discharge the drain when the bathtub stopper 16 is opened (S201). The system determines whether the bathtub water level has fallen below the reference water level (bathtub water level < reference water level) due to the bathtub tap 16 being opened and the bathtub water BW being drained (S202). If the bathtub water level < reference water level (YES in S202), the system starts timing the drain timer 144 (S203). The drain timer 144 times out after a certain period of time, such as three minutes, sufficient for the remaining bathtub water BW to be drained. The system determines whether the drain timer 144 has timed out (S204). The system waits until three minutes have passed, and after three minutes have passed, the system drives the circulation pump 18 to check whether there is any remaining hot water in the bathtub 14 (S205). The presence or absence of this remaining hot water can be determined by checking the output of the water flow switch 20, which is an example of a water flow detection means, to determine whether there is any remaining hot water flowing through the circulation path 12.

[0037] It is determined whether or not 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), S208 to S215 are skipped, this process is terminated, and drain D is not discharged. If there is no bath water BW (leftover bathwater) in the bathtub 14 (YES in S206), the circulation pump 18 is stopped (S208) and a drain discharge circuit is established (S209). The drain discharge circuit is a discharge path for drain D 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 stopper 16 is opened. A in Fig. 8 shows the amount of water at the initial water level, and B in Fig. 8 shows the state in which bathtub 14 is empty. At the timing of S209, bathtub 14 and circulation path 12 are empty, as shown in B in Fig. 8. After the drain discharge circuit is established, the circulation pump 18 is driven (S210), and 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 drain D has been discharged (S211). This determination can be made by measuring the time required to complete the discharge even if the drain tank 10 is full, or by detecting that the lower level detection electrode 40-2 of the drain tank 10 in FIG. 4 has fallen below the lower level Lref. If drain D has been discharged (YES in S211), the circulation pump 18 is stopped (S212), and a hot water supply circuit is established (S213). The hot water supply circuit is a hot water supply path that runs from the hot water supply pipe 82 through the water supply pipe 88 and the circulation path 12 to the bathtub 14. The hot water supply circuit is established by opening the hot water supply solenoid valve 104 of the water supply pipe 88, thereby establishing a state in which hot water HW can be poured into the bathtub 14. A certain amount of hot water is poured from this pouring circuit into the bathtub 14, for example, a volume W1 of water equivalent to a bathtub water level of 3 cm, to also clean the circulation path 12 (S214), and then the circulation pump 18 is driven for a predetermined period of time to drain the remaining water from the circulation path 12 (S215), thereby completing this process. If the bathtub stopper 16 is opened during the three minutes of S204, the bathtub 14 will be empty, as shown in A of Figure 9. If the three minutes of S204 are considered to be drained in this state and the bathtub stopper 16 is closed, the draining will be incomplete. In other words, as shown in B of Figure 9, the hot water poured (S214) in an amount W1 equivalent to a bathtub water level of 3 cm will remain in the bathtub 14, etc.

[0038] <Fully automated driving (1)> 10 shows the procedure for fully automatic operation [1] of the hot water reheating device 42. The procedure for 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 data storage can be performed only if the automatic operation switch 154 or the automatic operation switch 170 is turned on. It is determined whether the automatic operation switch 154 or the automatic operation switch 170 is turned on (S301), and if the automatic operation switch 154 or the automatic operation switch 170 is turned on (YES in S301), a predetermined amount of hot water, for example 10 liters, is poured (S302). The circulation pump 18 is driven and it is checked whether or not there is any remaining hot water (S303). If there is any remaining hot water (NO in S304), S307 to S317 are skipped, the circulation pump 18 is stopped (S305), and after draining the water, a re-execution command is output from the remote control device (S306), and this process ends. If there is no remaining hot water (YES in S304), the circulation pump 18 is stopped (S307), and a predetermined amount of hot water is poured again to fill the circulation path 12 with water, after which the two-way valve 122 is closed and pouring of hot water begins from the supply pipe 12-2 (S308).

[0039] While pouring hot water, the processes of S309 to S314 are performed. It is determined whether the bathtub water level sensor 24 has detected the initial water level (S309). If the initial water level is detected (YES in S309), the sensor value Lini and the water volume Vini are stored as the initial water level (S310). At this timing, the bathtub 14 is filled up to the initial water level, and the circulation path 12 and the like are filled with water, as shown in A of Fig. 8. In other words, the water volume Vini includes the water volume in the pipes. 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 is greater than or equal to 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, the water volume W1 corresponding to a water level of 3 cm in the bathtub 14 and the water volume W2 corresponding to a water level of 2 cm are calculated and stored. The following methods can be used to calculate W1 and W2. Pattern 1: The standard height of the circulation port is 15 cm. Therefore, from the initial water volume Vini stored in S310, W1=Vini / 15×3 (3) W2=Vini / 15×2 (4) Let's say. Pattern 2: In S311, the initial water level Lini + 3 (cm) is detected before the reference water level Lst (initial water level Lini + 8 (cm)) is detected, and the amount of molten metal poured after the initial water level detection when the initial water level Lini + 3 (cm) is reached is set to W1. The amount of water W2 is calculated based on the calculated W1. W2=W1 / 3×2 (5) Let's say. The calculation method is not limited to the above, and it is sufficient that the water volume W1 corresponds to a water level of 3 cm in each bathtub 14 and the water volume W2 corresponds to 2 cm. Pouring of molten metal continues, and it is determined whether the water level sensor value is equal to or greater than the set water level (water level sensor value ≧ set water level) (S314). If the water level sensor value is equal to or greater than the set water level (YES in S314), the water volume Vd per stage is stored as the set water level (S315). After storing this water volume Vd, the pouring of 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 terminated.

[0040] <Fully automated driving (2)> 11 shows the procedure for the fully automatic operation [2] of the hot water reheating device 42. The procedure for this automatic operation [2] is the operation after data storage by the automatic operation [1] (FIG. 8). In this processing procedure, it is determined whether automatic operation switch 154 or 170 is ON (S401), and if automatic operation switch 154 or 170 is ON (YES in S401), it is determined whether drainage was performed last time (S402). This is to confirm whether the drainage process of Fig. 7 was performed on bathtub 14 most recently, and whether the processes from S208 onwards have been performed. If drainage was not performed last time (NO in S402), S403 to S409 are skipped and the process proceeds to S410. If drainage was performed last time (YES in S402), the presence or absence of remaining hot water is checked by the bathtub water level sensor 24 (S403).

[0041] If there is remaining hot water (NO in S404), it is determined that water was poured without passing through the hot water reheating device 42 after drainage, and S405 to S409 are skipped and the process proceeds to S410. If there is no remaining hot water (YES in S404), the state is as shown in A or B of FIG. 9, which is the final state of the draining process in FIG. 7, and in this state the initial amount of hot water (= initial water amount Vini-W2) is poured (S405). As a result, in the case of A in Fig. 9, the state shown in A in Fig. 12 is reached, and the initial water level Lini is not reached. In addition, in the case of B in Fig. 9, the state shown in B in Fig. 12 is reached, and the initial water level Lini is exceeded. The circulation pump 18 is driven (S406), and it is determined whether the water flow switch 20 is ON (S407). If the water flow switch 20 is ON (YES in S407), the state is as shown in B in Figure 12, so a warning sound or a warning display, or both, is output to indicate a drainage abnormality (S408), and this process is terminated. If the water flow switch 20 is not turned on (NO in S407), the circulation pump 18 is stopped (S409), water is poured up to the set water level (S410), and the water is boiled to the set temperature (S411). In addition, the re-pouring of molten metal after draining may be configured to be performed after an alert is output and the alert is cleared after the drain has been discharged.

[0042] <Effects of Example 1> According to the first embodiment, the following effects can be obtained. (1) Even if the bathtub plug 16 of the bathtub 14 is accidentally closed when draining the drain D, the next time the bathtub 14 is filled with water, the system will automatically determine whether there is an abnormality based on the water level after the initial pouring of hot water, and will notify you of the abnormality by outputting an alert. (2) This alert can be given by voice or display from the bathroom remote control device or kitchen remote control device, allowing the user to easily recognize any abnormalities in drain discharge.

[0043] (3) If an abnormality in drain discharge is recognized, the bathtub plug 16 can be opened at that time to empty the bathtub 14. (4) Abnormalities in drain discharge can be detected by the initial amount of poured molten metal. If an abnormality occurs, drain D can be discharged from the bathtub by discharging the initial amount of poured molten metal, and the bathtub 14 can be cleaned at the same time. (5) If there is an abnormality in drain discharge, pouring of molten metal will be stopped after an alert is output, preventing waste of pouring molten metal. (6) In Example 1, after the drain D is discharged, a certain amount of water is poured as a cleaning pour. This improves the accuracy of detecting discharge abnormalities when there is little remaining drain D, and prevents drain D from remaining. (7) In a bathtub with a large volume, a constant amount of hot water, for example, 15 liters, can result in a water level of about 1 cm or less. Also, in a bathtub with a small area near the circulation port, such as a half-body bath, a constant amount of hot water, for example, 15 liters, can be too much, causing the water level to far exceed the circulation port. However, in Example 1, the water level determination is determined based on the individual installation situation and the bathtub, eliminating this inconvenience. For example, the amount of water poured after drain discharge is set to W1, which corresponds to a water level of 3 cm, based on the bathtub area at the height near the circulation port. Water is poured in at an amount W2, which corresponds to a water level of 2 cm, less than the initial amount, thereby improving the accuracy of water level determination. That is, after drain discharge, water equivalent to a water level of 3 cm is poured, and during the next automatic filling, hot water is poured to a level 2 cm lower than the position of the circulation port 22. If the circulation port 22 is submerged at this time, it is determined that drained water remains. (8) The bathtub water level can be measured by a water level sensor, and the water volume can be measured by the water volume sensor 92 and the water volume sensor 106. Taking into account measurement errors and residual water in the pipes, the bathtub water level can be estimated to be about 1 cm. In this embodiment, the following patterns 1 and 2 can be assumed as examples of how to calculate the water volume. 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 "amount of water poured up to that point / 15". This makes it possible to calculate the amount of water: 2 cm = W2, 3 cm = W1. In Pattern 2, after the initial water level is detected, the amount of water up to the initial water level + 3 cm is detected until the reference water level (initial water level + 8 cm) is detected by bathtub water level sensor 24, which is connected to circulation port 22 that drains when draining. The amount of water from this detected water level to the water level rise of 3 cm is set as the amount of water poured after draining, W1, and 2 / 3 of that is set as the amount of water W2 to reduce from the initial amount. Either Pattern 1 or Pattern 2 can improve the accuracy of determining whether drain D remains. [Example]

[0044] <Drain D discharge treatment> FIG. 13 shows a procedure for discharging the drain D according to the second embodiment. In the processing procedure of this embodiment 2, the drain discharge timing is detected and the drain is discharged, similarly to the discharge processing of embodiment 1. It is determined whether the drain level DL is equal to or higher than the upper level Href (DL≧Href) (S500). This drain level DL can 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 the process skips S501 to S504 and transitions to S505, where the drain discharge processing is performed. If the drain level DL is less than the upper level Href (NO in S500), the bathtub water level is monitored (S501) to detect the timing to discharge the drain by opening the bathtub stopper 16, and it is determined whether the bathtub water level is less than the reference water level (S502). If the bathtub water level is less than the reference water level, the drain timer 144 is started (S503), it is determined whether the time has expired on the drain timer 144 (S504), the circulation pump 18 is started, the remaining hot water is checked (S505), and it is determined whether there is any remaining hot water in the bathtub 14 (S506). If there is any remaining hot water in the bathtub 14 (NO in S506), the circulation pump 18 is stopped (S507), and S508 to S516 are skipped and the process ends, and the drain D is not discharged.

[0045] If there is no bathtub water BW (remaining hot water) in the bathtub 14 (YES in S506), 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), since there is no drain D to be discharged, S510 to S513 for normal pipe cleaning are skipped, and the process proceeds to S514. In this case, the amount of hot water injection in S515 may be a predetermined amount capable of cleaning the circulation path 12, for example, 10 [liters]. If DL ≥ Lref (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 to 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 (NO in S512), the discharge of drain D continues. If DL < Lref (YES in S512), the circulation pump 18 is stopped (S513), and a hot water injection circuit is established (S514). A certain amount of hot water injection is performed from the hot water injection circuit to the bathtub 14, which also serves to clean the circulation path 12. For example, hot water corresponding to a water volume W1 corresponding to a bathtub water level of 3 [cm] is injected (S515). Then, the circulation pump 18 is driven for a predetermined time to discharge the remaining water in the circulation path 12 (S516), and this process ends.

[0046] <Effect of Example 2> According to this Example 2, the following effects can be obtained. (1) When there is no accumulated drain, the drain discharge process can be omitted, and the drain discharge process can be performed only when drain D has accumulated, thus achieving process efficiency improvement. (2) By monitoring the drain level DL of the drain tank 10, the drain D accumulated in the drain tank 10 can be reliably discharged. (3) 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 falls below the lower level Lref, which is a reference level. This minimizes the pump drive time for drain discharge. [Example]

[0047] 14 shows a hot water reheating device 42 according to Example 3. Example 3 is a specific implementation of the hot water reheating device 42 of Example 1. In this third embodiment, the combustion chambers 44-1, 44-2 and intake fans 76-1, 76-2 of the first embodiment are configured into a single combustion chamber 44 and a single intake fan 76, thereby making the system more compact. 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. The other configurations are the same as those in FIG. 5, so the same parts are given the same reference numerals and the explanation of each member is omitted.

[0048] <Effects of Example 3> According to this Example 3, the same effects as those of the embodiment, Example 1, and Example 2 described above can be obtained, and in addition to making the device more compact, it is possible to prevent drain D from remaining in the bathtub 14, and it is possible to clean the inside of the bathtub 14 in a hot water reheating device that can be operated fully automatically.

[0049] Other Embodiments (1) In the above embodiment, the discharge of the drain D is described separately for the first and second embodiments, but the configuration may include both of these. (2) In the above embodiment, the hot water supply and reheating functions are described, but the present invention may be applied to a hot water supply, reheating and heating device with a heating function, or to a heat medium heating device. (3) In the drain discharge process (FIG. 7), pouring of hot water is exemplified in S214, but pouring of water may be performed instead of pouring of hot water without burner combustion and heat exchange.

[0050] As explained above, the most preferred embodiments of the drain discharge method, drain discharge device, and water heater have been described. The present invention is not limited to the above description. Various modifications and changes are possible for those skilled in the art based on the gist of the invention as set forth 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. [Industrial Applicability]

[0051] According to the present invention, even if the bathtub plug is accidentally closed when draining drain D into the bathtub, the drain D discharge abnormality can be determined by the water pouring operation, and the abnormality is notified by an alert, which is advantageous in that it is possible to prevent the inconvenience of residual drain from occurring. [Explanation of symbols]

[0052] 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 stopper 18 Circulation Pump 20 Water flow switch 22 Circulation port 24 Bathtub water level sensor 26 Bathtub bottom 28 Bathtub Data Table 30 Bathtub Information 32 Water level information 32-1 Initial water level information 32-2 Reference water level information 32-3 Set water level information 34 Introduction Port 36 Exhaust 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 Reheating combustion chamber 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 Main 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 intake fan 80 Water supply pipe 82 Hot water pipe 86 Bypass pipe 88 Water injection pipe 90 Water supply temperature sensor 92 Water level sensor 96 Outlet water temperature sensor 98 Water Control Valve 100 Mixed temperature sensor 102 Bypass solenoid valve 104 Solenoid valve for pouring hot water 106 Pouring amount sensor 108 Check valve 110 Drain pan 112, 114 Drain pipe 113 Neutralizer 116 Check valve 118, 120 Temperature sensor 122 Two-way valve 124 Three-way valve 128 Control Unit 130 Hot water supply control unit 132 Bathroom remote control control unit 134 Kitchen remote control control unit 136, 146, 162 processors 138, 148, 164 memory section 140, 150, 166 Communications Department 142, 152, 168 input / output section 154, 170 Automatic driving switch 156, 172 LEDs 158, 174 LCD display 160, 176 speakers 178, 180 exhaust port

Claims

1. A drainage method for discharging drainage generated in a water heater and stored in a drain tank through a bathtub, comprising: A process of discharging the drain from the drain tank into the bathtub when bathtub water is being discharged from the bathtub, or when the drain in the drain tank exceeds a reference level and the bathtub water does not flow into a circulation path connected to the bathtub by driving a circulation pump; a step of outputting alert information when the drain from the drain tank is completed, an amount of water is poured into the bathtub so that the circulation port is not partially or completely submerged, and then the circulation pump is driven to cause the bathtub water to flow into the circulation path connected to the bathtub; A drain discharge method including:

2. A drain discharge device that discharges drain generated in a water heater and stored in a drain tank through a bathtub, a level sensor that detects the level of drain stored in the drain tank; a drain discharge path that discharges the drain from the drain tank into the bathtub; a circulation path and a circulation pump for circulating bathwater in the bathtub; a control unit that outputs alert information when bathtub water is being drained from the bathtub, or when the drain in the drain tank exceeds a reference level and the bathtub water does not flow into the circulation path by driving the circulation pump, drains the drain from the drain tank into the bathtub, stops draining the drain from the drain tank, and pours water into the bathtub in an amount that does not submerge part or all of the circulation port, and then drives the circulation pump to cause the bathtub water to flow into the circulation path connected to the bathtub; A drain discharge device including:

3. A hot water supply apparatus that discharges drain stored in a drain tank through a bathtub, the hot water supply apparatus including the drain discharge device according to claim 2.

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