Drain discharge method, discharge device and water heater

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, heat of combustion of fuel gas is exchanged with feed water or the like. [Background technology]

[0002] Drainage occurs in the heat exchanger when the combustion heat of fuel gas is exchanged with water supply, but the generation of drainage is particularly noticeable in high-efficiency hot water heaters equipped with a secondary heat exchanger that recovers the latent heat of combustion. After being neutralized in a neutralizer, this drainage is stored in a drain tank and discharged through the bathtub when the bathtub plug is opened. Regarding drainage, it is known that the drain in the drain tank is diluted or neutralized and then drained 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 drainage timing (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-265228 A [Patent Document 2] JP 2009-270798 A Summary of the Invention [Problem to be solved by the invention]

[0004] By the way, when drainage from the drain tank is discharged through the bathtub, the bathtub is simply used as a drainage path and the drainage is not 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, water is supplied to the bathtub through the circulation path after the drainage is discharged, so that the drainage does not remain in the piping of the circulation path or in the bathtub. This drain discharge is based on the premise that the bathtub plug is open, and if the bathtub plug is accidentally closed, the drain being discharged will remain in the circulation path and bathtub, and the drain will mix with the bathtub water. Even if a specified amount of water or hot water is supplied for cleaning, if the plug is closed, the drain cannot be discharged from the bathtub. If a user does not notice this drain discharge and closes the bathtub plug and switches to automatic hot water supply, there is a risk that such drain will remain, and if the drain mixes with the bathtub water, there is a problem that it is impossible to determine whether the drain has mixed with the bathtub water because the drain is colorless and transparent. Incidentally, the inventor of the present application has found that when drain is discharged into the 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 filled automatically, the amount of water poured in that is less than the initial water level can be used to check whether the amount of drain remains. However, based on this finding, the inventor has found that when a fixed amount of water is poured in, the water level differs depending on the volume of the bathtub and the shape of the inside of the bathtub, so the judgment results vary and there are cases where it is not possible to check whether drain remains.

[0005] In view of the above problems, an object of the present invention is to determine whether drain remains by pouring water after drainage and to encourage the user to drain the drain. In consideration 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 when a certain amount of water is poured, thereby improving the accuracy of drain discharge and pouring water without being affected by the volume of the bathtub or the shape of the interior of the bathtub. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, according to one aspect of the drain discharge method of the present invention, the method discharges drain stored in a drain tank through a bathtub, and includes the steps of: discharging the drain from the drain tank into the bathtub when bath 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 in the pump circulation of the bathtub water; and outputting alert information or stopping the pouring of water into the bathtub when there is a water flow in the pump circulation after finishing the discharge of the drain from the drain tank and pouring an amount of water into the bathtub such that a part or all of the circulation port is not submerged.

[0007] In order to achieve the above-mentioned object, according to one aspect of the drain discharge device of the present invention, there is provided a drain discharge device that discharges drain stored in a drain tank through a bathtub, and includes 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 that circulates bath water in the bathtub, and a control unit that discharges the drain from the drain tank into the bathtub when bath 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 in the pump circulation of the bathtub water, stops discharging the drain from the drain tank, and outputs alert information or stops pouring of water into the bathtub when there is a water flow in the pump circulation after pouring an amount of water into the bathtub such that a part or all of the circulation port is not submerged.

[0008] In order to achieve the above object, one aspect of a 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. Effect of the Invention

[0009] According to the present invention, any 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 stopper is closed, the user can open the bathtub stopper when the alert is output, which will allow the drain to be drained from the bathtub, which has a certain amount of water in it, making it possible to fill the bathtub with water without drainage. (3) The drain remaining in the bathtub is diluted by the initial water pouring in, so that by opening the bathtub plug, the drain can be drained and the bathtub can be purified, making it possible to pour water into the bathtub without containing any drain. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a drain discharge device according to an embodiment. [Diagram 2] 1 is a flowchart showing a drain discharge process. [Diagram 3] FIG. 1A is a diagram showing a bathtub water level setting according to the first embodiment, and FIG. [Figure 4] FIG. 1A is a front view showing the drain tank, and FIG. [Diagram 5] FIG. 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] 1 is a flowchart showing a first processing procedure for drainage. [Figure 8] FIG. 1A shows the initial water injection operation, and FIG. 1B 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] 1 is a flowchart showing a first processing procedure for fully automatic driving. [Figure 11] 11 is a flowchart showing a second processing procedure for fully automatic driving. [Figure 12] FIG. 1A shows a normal drainage state, and FIG. 1B 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. 11 is a diagram showing a hot water reheating device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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] Drain discharge unit 4 discharges drainage, for example, either when bathtub 14 is drained by opening bathtub plug 16, or when drain D exceeds reference level Dref, which is an example of drain tank 10, and it is confirmed that no water flow is occurring due to circulation of bathtub water BW by circulation pump 18. The presence or absence of water flow is detected by water flow switch 20, which is an example of water flow detection means. After drain D is discharged, water injection unit 6 injects a fixed amount of water. The fixed amount of water is injected into bathtub 14 when it is empty with bathtub stopper 16 closed, and serves to clean the drain discharge circuit described below. Even if the initial water injection is an amount of water that is less than the amount of water that would submerge part or all of circulation port 22, the amount of water that will submerge part or all of circulation port 22 after the addition of the fixed amount of water is sufficient. 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 the output of the water flow switch 20.

[0013] <Drain discharge process> 2 includes a process for drain discharge and detection of discharge abnormality 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, and includes the discharge of drain D, decision to discharge drain D, pouring water, decision on the water level of bathtub 14, and output of alert information. It is determined whether it is the first or second drain timing for draining the drain D (S11). The first drain timing is the timing when the bathtub 14 is drained after the bathtub plug 16 is opened. The second drain timing is the timing when it is confirmed that the drain D exceeds the reference level Dref described above in the drain tank 10 and that no water flow is generated by the pump circulation of the bathtub water BW. This timing occurs, for example, when the drain D exceeds the upper level Href (FIGS. 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 from the drain discharge circuit including the circulation path 12 to the bathtub 14 (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 drainage of the drain D has been completed (S14), and if drainage of the drain D from the drain tank 10 is completed (YES in S14), a certain amount of water W1 equivalent to, for example, 3 cm of the bathtub water level is poured from the water injection unit 6 to wash the drain discharge circuit including the circulation path 12 (S15). This completes the 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 of water W2 equivalent to, for example, 2 cm of the bathtub water level. When pouring water, bathtub plug 16 is in the closed state.

[0016] It is then determined whether or not the circulation port 22 has been 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 the circulation port 22 is not partially or completely submerged (NO in S17), the drain D has been discharged from the bathtub 14, and so no alert information is output (S18). If the circulation port 22 is partially or completely submerged (YES in S17), an alert is output indicating that drain D remains in the bathtub 14, or an alert indicating that water filling has been stopped (S19). This alert can prompt the user to open the bathtub plug 16, i.e., to drain the bathtub.

[0017] <Effects of the embodiment> According to this embodiment, the following effects can be obtained. (1) The next time water is poured in, i.e., when the tub is filled with water, an alarm will sound to let you know if there is any drain remaining from the previous drainage during the initial hot water supply. (2) If there is an alarm indicating the stopping of water supply or an alarm indicating residual drainage, you can simply drain the bathtub at that point in time to prevent residual drainage. EXAMPLES

[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, from the initial water level Lini. The set water level L1 is set to a certain height, for example, about 3 cm, from the standard water level Lst, and each set water level L1, L2, L3, ... L11 has a certain width in the height 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 surface 26 to the set water level L11 is Set water level L11 height = 15 [cm] + 8 [cm] + 3 [cm] x 11 =56 [cm] (2) It is.

[0021] If the resolution of bathtub water level sensor 24 is 1 bit = 0.2125 [cm], then 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 are values ​​that differ depending on the piping and the bathtub 14.

[0022] <Bathtub Data Table 28> 3B shows a bathtub data table 28. This bathtub data table 28 is a database of bathtub data, and stores installation information, water level information, and the like 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 about the installation status, size, etc. of bathtub 14.

[0023] The initial water level information 32-1 stores the water volume Vini from the bathtub bottom surface 26 to the initial water level Lini, including the water volume in the piping. The water volume Vini is a measurement value of the bathtub water level sensor 24. The reference water level information 32-2 stores a reference water volume Vst from the initial water level Lini to the reference water level Lst. This reference water volume Vst is a 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 embodiment 1, 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, stored therein, and 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 the drain D accumulated in the drain tank 10. The drain level sensor 40 is provided 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 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 places other than the bathtub 14, hot water supply for supplying hot water to the bathtub 14, and a reheating function for bath water BW.

[0026] This hot water reheating device 42 is equipped with a hot water combustion chamber 44-1 and a reheating combustion chamber 44-2. The hot water combustion chamber 44-1 is equipped 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 of the combustion exhaust 60 obtained by the combustion of the burner 58 with the bath water BW. The heat exchangers 48, 50, 56 can be operated in either a bidirectional or independent manner, and the hot water HW obtained by the heat exchange of the primary heat exchanger 48 and the secondary heat exchanger 50 for hot water supply can be poured into the bathtub 14.

[0027] A fuel gas supply pipe 62 is connected to the burners 52 and 58, and fuel gas G is supplied to them. A main 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, and a gas solenoid valve 74 is installed on the burner 58 side. An air supply fan 76-1 is provided on the burner 52 side as an air supply means, and an air supply fan 76-2 is provided on the burner 58 side, and the air required for burner combustion is supplied. Therefore, for hot water supply, hot water pouring or reheating of bath water BW, the amount of gas combustion of the burners 52 and 58 required to control the hot water supply temperature, hot water pouring temperature and reheating temperature is controlled by the opening of the gas proportional valve 66 etc.

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

[0029] The feed water temperature sensor 90 detects the feed water temperature. The water volume sensor 92 detects the volume of feed water flowing through the feed water 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 feed water W to be mixed with the hot water HW. The water control valve 98 is used to control the volume of feed water and hot water. The mixed temperature sensor 100 detects the temperature of the mixed water of the hot water HW and the feed water 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 poured into the bathtub 14. The water supply amount sensor 106 measures the amount of water poured. The check valve 108 is a means for isolating the water supply pipe 80 and the hot water supply pipe 82 from the bath water 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 to a neutralizer 113 through a drain pipe 112, where it is neutralized, and then stored in the drain tank 10. The drain D in the drain tank 10 is led to the return pipe 12-1 of the circulation path 12 through a drain pipe 114. A check valve 116 is provided in the drain pipe 114. The check valve 116 is a means for isolating the circulation path 12 and 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 pour drain D from the drain pipe 114 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 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 an operating system (OS), a hot water reheating program, a drain discharge program, and the like stored in the memory unit 138. The memory unit 138 is composed of storage elements such as a read-only memory (ROM), a random-access memory (RAM), and an electrically erasable programmable read-only memory (EEPROM), and the ROM or EEPROM stores the OS, the hot water reheating program, the 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 control unit 134 and the communication unit 150 of the bathroom remote control control unit 132. The I / O 142 is used to take in outputs from the water flow switch 20, bathtub water level sensor 24, drain level sensor 40, water pouring volume sensor 106, drain timer 144, etc., and to take out control outputs to the circulation pump 18, water control valve 98, water pouring solenoid valve 104, two-way valve 122, three-way valve 124, etc. The drain timer 144 is used to measure a certain period of time, for example, three minutes, as a standby time for draining the drain D.

[0034] Like 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 152. The processor 146 controls the link 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 on 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 linkage with the hot water supply control unit 130, starts automatic operation and indicates it, 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 on a liquid crystal display 174, and take out audio output from a speaker 176.

[0036] <Drain D discharge treatment> FIG. 7 shows the drain D discharge process of the hot water reheating device 42. The hot water HW after heat exchange is used for this drainage process. In this process, the drain discharge timing is detected and the drain is discharged. It is determined whether the drain level DL is equal to or higher than the upper level Href (DL≧Href) (S200). 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 S201 to S204 are skipped and the process proceeds to S205, where the drain discharge process is started. 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 by opening the bathtub plug 16 (S201). It is determined whether the bathtub water level has fallen below the reference water level (bathtub water level < reference water level) due to the bathtub plug 16 being opened and the bathtub water BW being drained (S202). If the bathtub water level < 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 for the remaining bathtub water BW to be drained. It is determined whether the drain timer 144 has timed out (S204). It waits until three minutes have passed, and after three minutes have passed, it 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 the output of the water flow switch 20, which is an example of a water flow detection means, by checking whether there is any remaining hot water flowing in the circulation path 12.

[0037] It is determined whether or not there is remaining hot water in the bathtub 14 (S206), and if there is 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 (remaining bath water) 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. 8A shows the amount of water at the initial water level, and FIG 8B 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 FIG 8B. After the drain discharge circuit is established, the circulation pump 18 is driven (S210) to discharge the drain D from the drain tank 10 to the bathtub 14 through the drain discharge circuit. While the circulation pump 18 is operating, it is determined whether the discharge of the drain D has been completed (S211). The determination of the completion of the discharge may be made by measuring the time during which the drain D in the drain tank 10 can be completed even if the drain D 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 the discharge of the drain D has been completed (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 supply path for hot water from the hot water supply pipe 82 through the water supply pipe 88 and the circulation path 12 to the bathtub 14. The establishment of the hot water supply circuit is achieved by opening the hot water supply solenoid valve 104 of the water supply pipe 88 and establishing a state in which hot water HW can be poured into the bathtub 14. A certain amount of molten water is poured from this pouring circuit into the bathtub 14 to clean the circulation path 12, for example, a volume W1 of water equivalent to a bathtub water level of 3 cm (S214), and then the circulation pump 18 is driven for a predetermined period of time to drain the remaining water in the circulation path 12 (S215), thereby completing this process. If the bathtub plug 16 is opened during the three minutes of S204, the bathtub 14 will be empty, as shown in A of Fig. 9. If the drainage is deemed to be complete in this state during the three minutes of S204 and the bathtub plug 16 is closed, the drainage will be incomplete. In other words, as shown in B of Fig. 9, the drain D and the amount of water W1 poured (S214) equivalent to a bathtub water level of 3 cm will remain in the bathtub 14, etc.

[0038] <Fully automatic operation〔1〕> Fig. 10 shows the procedure for the fully automatic operation [1] of the hot water reheating device 42. The procedure for the 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, etc. 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, the automatic operation switch 154 or the automatic operation switch 170 must be turned on. 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 in S301), a predetermined amount of hot water, for example 10 [liters], is poured (S302). The circulation pump 18 is driven, and the presence or absence of remaining hot water is confirmed (S303). If there is remaining hot water (NO in S304), S307 to S317 are skipped, the circulation pump 18 is stopped (S305), and after draining, 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 that, the two-way valve 122 is closed and pouring of hot water begins from the supply pipe 12-2 (S308).

[0039] While pouring, the processes of S309 to S314 are performed. 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 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=measurement value-Lini) and water volume (Vst=measurement 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 us assume that. 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 us assume that. 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 a water level of 2 cm. Pouring of molten metal 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 ≧ 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, pouring 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), after which this process is terminated.

[0040] <Fully automatic operation〔2〕> Fig. 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 process, 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 in S401), it is determined whether drainage was performed last time (S402). This is to check whether the drainage process of Fig. 7 was performed most recently for the bathtub 14, and whether the process from S208 onwards has been performed. If drainage was not performed last time (NO in S402), S403 to S409 are skipped and the process transitions to S410. If drainage was performed last time (YES in S402), the presence or absence of remaining 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 the drain was discharged, 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 drainage process in FIG. 7, and in this state the initial amount of hot water (=initial amount of water 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. Also, 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 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 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 resumption of pouring after draining may 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 system will automatically determine an abnormality the next time the bathtub 14 is filled with water based on the water level after the initial pouring, and will notify the user of the abnormality by issuing an alert. (2) This alert can be notified 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 point and the bathtub 14 can be emptied. (4) Abnormalities in drain discharge can be detected by checking the initial amount of molten metal poured. If an abnormality occurs, drain D can be discharged outside the bathtub by pouring the molten metal into the bathtub. At the same time, the bathtub 14 can be cleaned using the initial amount of molten metal poured. (5) If there is an abnormality in the drain discharge, pouring will stop after the alert is output, preventing the waste of pouring. (6) In the first embodiment, after the drain D is discharged, a certain amount of water is poured as cleaning water. This improves the accuracy of detecting discharge abnormalities when the amount of remaining drain D is small, and prevents drain D from remaining. (7) In the case of a large bathtub, if the volume of the bathtub is, for example, 15 liters, the water level will be about 1 cm or less. In addition, in the case of a bathtub with a small area near the circulation port, such as a bathtub for a half-body bath, if the volume of the bathtub is, for example, 15 liters, the water level will be too much and will be far above the circulation port. In contrast, in the first embodiment, the judgment water volume is determined according to the individual installation situation and the bathtub, so that such inconveniences can be eliminated. For example, the amount of water poured after drain discharge is set to the amount of water W1 equivalent to a water level of 3 cm based on the bathtub area at the height position near the circulation port, and water is poured by an amount W2 equivalent to a water level of 2 cm less than the initial water volume, so that the accuracy of the water level judgment can be improved. In other words, water equivalent to a water level of 3 cm is poured after drain discharge, and at the next automatic filling, water is poured to a water level 2 cm lower than the position of the circulation port 22. If the circulation port 22 is submerged at that time, it is determined that drain discharge water remains. (8) The bathtub water level can be measured by the water level sensor, and the water volume can be measured by the water volume sensor 92 and the pouring water volume sensor 106. Taking into account measurement errors and residual water in the pipes, the bathtub water level can be estimated at about 1 cm. In this embodiment, the following Pattern 1 and Pattern 2 can be assumed as examples of methods for calculating 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 allows the water amounts of 2 cm = W2 and 3 cm = W1 to be calculated. In pattern 2, after the detection of the initial water level, the amount of water up to the initial water level + 3 [cm] is detected by the bathtub water level sensor 24 connected to the circulation port 22 that drains when the drain is discharged. The amount of water up to the water level rise of 3 [cm] from this detected water level is set as the amount of water poured in after drain discharge W1, and 2 / 3 of that amount is set as the amount of water W2 that is reduced from the initial amount. Either pattern 1 or pattern 2 can improve the accuracy of determining whether drain D remains. EXAMPLES

[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 the second embodiment, detection of drain discharge timing and drain discharge are performed in the same manner as in the drain discharge processing of the first embodiment. 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 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 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 drain timer 144 has timed out (S504), the circulation pump 18 is started, the remaining water is checked (S505), and it is determined whether there is remaining water in the bathtub 14 (S506). If there is remaining water in the bathtub 14 (NO in S506), the circulation pump 18 is stopped (S507), 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 is not less than Lref (NO in S509), the drain discharge circuit is established (S510), the circulation pump 18 is driven (S511), and the 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 is not less than Lref (NO in S512), the discharge of the drain D continues. If DL < Lref (YES in S512), the circulation pump 18 is stopped (S513), and the 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 as cleaning of the circulation path 12. For example, hot water injection of the amount W1 corresponding to a bathtub water level of 3 [cm] is performed (S515). Then, the circulation pump 18 is driven for a predetermined time to discharge the residual 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 the drain D has accumulated, thereby improving the processing efficiency. (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, so that the pump drive time for drain discharge can be minimized. EXAMPLES

[0047] Fig. 14 shows a hot water reheating device 42 according to Example 3. Example 3 is obtained by configuring the hot water reheating device 42 of Example 1 at a specific implementation level. In the 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 facilitate ventilation within the apparatus. The other configuration is the same as in FIG. 5, so the same parts are given the same reference numerals and the description 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 to purify the inside of the bathtub 14 in a hot water reheating device that is capable of fully automatic operation.

[0049] Other Embodiments (1) In the above embodiment, the discharge of the drain D is described separately for embodiment 1 and embodiment 2, but a configuration including both of these may be used. (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 / heating device having a heating function, or may be applied 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 used 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 hot water supply device 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 described in the claims or disclosed in the description for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention. [Industrial Applicability]

[0051] According to the present invention, even if the bathtub plug is mistakenly 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, so that the inconvenience of residual drain can be avoided in advance, which is advantageous. [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 Hot water combustion chamber 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 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 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 Pouring solenoid valve 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 unit 134 Kitchen remote 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 drain stored in a drain tank through a bathtub, comprising the steps of: Discharging the drain from the drain tank into the bathtub when the bathtub water is being drained from the bathtub or when the drain in the drain tank exceeds a reference level and there is no water flow due to the pump circulation of the bathtub water; A step of finishing discharging the drain from the drain tank, pouring water into the bathtub in an amount that does not submerge a part or all of the circulation port, and then outputting an alert or stopping the pouring of water into the bathtub when there is a water flow due to the pump circulation; A drain discharge method comprising:

2. A drain discharge device that discharges drain stored in a drain tank through a bathtub, a level sensor for detecting a level of the drain stored in the drain tank; A drain discharge path for discharging the drain of the drain tank into the bathtub; A circulation path and a circulation pump for circulating bath water in the bathtub; a control unit which, when bath water is being drained 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, drains the drain from the drain tank into the bathtub, stops draining the drain from the drain tank, and outputs alert information or stops pouring water into the bathtub when there is water flow from the pump circulation after pouring an amount of water into the bathtub that does not submerge a part or all of the circulation port; A drain discharge device comprising:

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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