JP2018162922A - Electric water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric water heater capable of inhibiting hot water from continuously remaining in a hot water storage tank when a power source is abnormal.SOLUTION: An electric water heater includes: a water feed pipe; a hot water storage tank for heating water to convert it to hot water; a hot water side solenoid valve for discharging the hot water in the hot water storage tank; a water side solenoid valve for discharging the water from the water feed pipe; a control section for controlling opening/closing of the water side solenoid valve and the hot water side solenoid valve; and an abnormality detection section for detecting abnormality of a power source. Based on a signal of the abnormality detection section, when the power source is abnormal, the control section executes an emergency mode of preferentially opening the hot water side solenoid valve as compared with the water side solenoid valve.SELECTED DRAWING: Figure 1

Description

  Aspects of the invention generally relate to an electric water heater.

  A faucet device capable of discharging water and hot water is provided with, for example, an electric water heater that heats water to make hot water. The electric water heater has, for example, a hot water storage tank that heats water, a hot water side electromagnetic valve that opens and closes the flow path of hot water, and a water side electromagnetic valve that opens and closes the flow path of water. When the hot water side solenoid valve is opened, hot water is discharged from the faucet device, and when the water side solenoid valve is opened, water is discharged from the faucet device.

  An electric water heater usually operates with electric power supplied from a power source such as a commercial power source. When the power supply is abnormal, for example, at the time of a power failure, the power supply for supplying power to the electric water heater is switched to an emergency power supply provided in a facility provided with the electric water heater. In the case of such an abnormality in the power source, conventionally, heating of water by the hot water storage tank has been sometimes stopped in order to reduce power consumption. Further, in connection with this, there are cases where both the hot water side solenoid valve and the water side solenoid valve are not driven, and only the water side solenoid valve is driven.

JP 2014-189963 A

  However, when the hot water side solenoid valve is not driven, the same hot water (water) remains in the hot water storage tank for a long time until the power source returns to the normal state. When the heating of the water in the hot water storage tank is stopped, the temperature of the hot water may decrease with the passage of time, and may become a temperature at which germs can easily propagate. For this reason, there existed a possibility that a microbe may propagate in the hot water (water) which stayed in the hot water storage tank. Further, after the power source returns to the normal state, the water in the hot water storage tank can be sterilized again, but there is a possibility that the user may feel uncomfortable.

  The present invention has been made based on recognition of such a problem, and an object of the present invention is to provide an electric water heater that can prevent hot water from remaining in the hot water storage tank when the power supply is abnormal.

  1st invention is a water supply pipe, a hot water storage tank which heats water to make hot water, a hot water side solenoid valve for discharging hot water in the hot water storage tank, and a water side for discharging water from the water supply pipe An electromagnetic valve; a control unit that controls opening and closing of the water side solenoid valve and the hot water side solenoid valve; and an abnormality detection unit that detects an abnormality of a power source, and the control unit outputs a signal of the abnormality detection unit. The electric water heater is characterized by executing an emergency mode in which the hot water side solenoid valve is opened with priority over the water side solenoid valve when the power supply is abnormal.

  According to this electric water heater, when hot water in the hot water storage tank is preferentially used when the power supply is abnormal, it is possible to prevent hot water from remaining in the hot water storage tank. Thereby, the comfort of the user who wants to use hot water can be ensured. Moreover, since hot water can be used up at an early stage, the propagation of bacteria can be suppressed and hygiene can be ensured.

  A second invention further includes a storage device that stores a time when the hot water side solenoid valve is opened in the first invention, wherein the control unit stores the storage device during the execution of the emergency mode. An electric water heater that controls opening and closing of the water-side solenoid valve and the hot water-side solenoid valve based on time.

  According to this electric water heater, it is possible to estimate the amount of hot water remaining in the hot water storage tank from the start of execution of the emergency mode based on the time when the hot water side solenoid valve is opened. Based on this time, by preferentially using the hot water in the tank, it is possible to suppress the growth of bacteria and ensure hygiene.

  According to a third aspect, in the first or second aspect, the control unit opens the water side solenoid valve and the hot water side solenoid valve during the execution of the emergency mode, and the frequency at which the hot water side solenoid valve opens. The electric water heater is characterized in that the water side solenoid valve is opened more frequently.

  According to this electric water heater, by preferentially using the hot water in the hot water storage tank, the water in the water supply pipe is replaced by opening the water side solenoid valve while ensuring the comfort and hygiene of the user. The growth of bacteria in the water supply pipe can be suppressed.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, an operation unit that switches between a water discharge mode for operating the water side electromagnetic valve and a hot water discharge mode for operating the hot water side electromagnetic valve. Further, the electric water heater according to claim 1, wherein the control unit enters the water discharge mode when it is determined that the operation unit is operated during execution of the emergency mode.

  According to this electric water heater, the user can use water by operating the operation unit even during the execution of the emergency mode in which priority is given to the use of hot water. Therefore, user convenience can be improved.

  According to a fifth invention, in any one of the first to fourth inventions, the control unit is after the end of the discharge of hot water in the hot water storage tank during execution of the emergency mode, and the previous time The electric water heater is characterized in that only the water-side solenoid valve is opened after a lapse of a predetermined time from the opening operation of the hot water-side solenoid valve.

  According to this electric water heater, when a predetermined time has elapsed from the opening operation of the hot water side solenoid valve, only the water side solenoid valve is opened so that the hot water (water ) Is not discharged. When the predetermined time has not elapsed, the hot water side solenoid valve is preferentially opened to replace the hot water (water) in the hot water storage tank to suppress the growth of bacteria. Thereby, hygiene can be ensured.

  In a sixth aspect based on any one of the first to fifth aspects, when the hot water side electromagnetic valve and the water side electromagnetic valve are closed, the control unit is It is an electric water heater characterized by determining which of the water side solenoid valves is opened.

  According to this electric water heater, when water or hot water is being discharged, the open solenoid valve is not switched unintentionally and the water temperature does not change suddenly. .

  According to the aspect of the present invention, there is provided an electric water heater that can prevent hot water from remaining in the hot water storage tank when the power supply is abnormal.

It is a top view which illustrates the water faucet device provided with the electric water heater concerning an embodiment. It is a schematic diagram which illustrates the flow path of the electric water heater which concerns on embodiment. It is a block diagram which illustrates the electric water heater which concerns on embodiment. It is a flowchart which illustrates operation | movement of the electric water heater which concerns on embodiment. It is a flowchart which illustrates operation | movement of the electric water heater which concerns on embodiment. It is a flowchart which illustrates operation | movement of the abnormality detection part which concerns on embodiment. It is a graph which illustrates the waveform of the voltage of a commercial power source. It is a graph which illustrates the waveform of the voltage of an emergency power supply.

Embodiments of the present invention will be described below with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.
FIG. 1 is a plan view illustrating a water faucet device provided with an electric water heater according to an embodiment.
The faucet device 200 shown in FIG. 1 is provided with an electric water heater 100, a discharge unit 80, a sensor 82, a changeover switch 84, and a water discharge switch 85 according to the embodiment.

  The electric water heater 100 has a water supply port 51 and a hot water outlet (water outlet) 52. The water supply port 51 is connected to a water supply source 71 such as a water pipe through a pipe 72. Thereby, water is supplied from the water supply source 71 to the electric water heater 100. The electric water heater 100 heats the supplied water as necessary to make hot water (hot water).

  The hot water outlet 52 is connected to the discharge unit 80 via a pipe 73. The water (or hot water) supplied to the electric water heater 100 is guided from the hot water outlet 52 to the discharge unit 80. The discharge unit 80 discharges the water that has passed through the electric water heater 100 to the bowl 86.

FIG. 2 is a schematic view illustrating the flow path of the electric water heater according to the embodiment.
As shown in FIG. 2, the electric water heater 100 includes a water supply channel 10 and a hot water channel 20. The flow path of the water supplied from the water supply port 51 branches into the water supply flow path 10 and the hot water supply flow path 20 at the branch point P1. The branched water supply channel 10 and hot water supply channel 20 merge at a junction P2 before the hot water outlet 52.

  The water supply channel 10 includes a water side electromagnetic valve 11 and a water supply pipe 12. The water side solenoid valve 11 and the water supply pipe 12 are provided between the branch point P1 and the junction P2. The water supply pipe 12 is provided downstream of the water side electromagnetic valve 11 and is connected to the hot water outlet 52. The water that has flowed into the water supply channel 10 is guided to the hot water outlet 52 through the water supply pipe 12.

  The water side electromagnetic valve 11 is an electromagnetic valve for discharging water from the water supply pipe 12. That is, the water-side electromagnetic valve 11 is an electromagnetic valve that opens and closes the water supply flow path 10, and water flows into the water supply flow path 10 by opening the water-side electromagnetic valve 11. The inflowing water flows from the hot water outlet 52 to the discharge section 80 and is discharged.

  As the water side electromagnetic valve 11, for example, a latch type electromagnetic valve is used. The latch type solenoid valve switches the open / closed state of the flow path by moving the plunger by energizing the solenoid coil. When the open state or the closed state of the flow path is maintained, the electromagnetic valve holds the plunger using the magnetic force of the permanent magnet or the elastic force of the spring. On the other hand, when switching between the open state and the closed state (during driving), electric power is supplied and the plunger moves. Therefore, electric power is supplied to the solenoid valve only when the flow path is switched between open and closed states.

  The hot water supply channel 20 includes a hot water side solenoid valve 21, a hot water storage tank 22, a pipe (water channel) 23, a mixing valve 24, and a tube (warm water channel) 25. These are provided between the branch point P1 and the junction point P2. The downstream side of the hot water side solenoid valve 21 branches into a hot water storage tank 22 and a pipe 23. The hot water storage tank 22 and the pipe 23 are each connected to a downstream mixing valve 24.

  The hot water storage tank 22 has a heating unit (for example, an electric heater) that heats water that has flowed into the hot water storage tank 22. Thereby, the hot water storage tank 22 heats water to make hot water. The temperature of the hot water is, for example, about 70 to 80 ° C. In the present specification, the temperature of hot water is not limited to the above, and water having a temperature higher than normal temperature is called hot water. Further, even if the water is not heated by the hot water storage tank 22, the water that has passed through the hot water supply channel 20 may be referred to as hot water. Even when the water is heated to the normal temperature after being heated by the hot water storage tank 22, the water that has passed through the hot water supply channel 20 may be referred to as hot water.

  A part of the water flowing into the hot water supply channel 20 flows into the hot water storage tank 22, is appropriately heated, and is guided to the mixing valve 24. Another part of the water that has flowed into the hot water supply channel 20 is guided to the mixing valve 24 by the pipe 23 while maintaining the room temperature.

  The mixing valve 24 has, for example, a thermostat, and has a temperature adjustment function of mixing hot water and water to obtain an appropriate temperature. For the thermostat, for example, a mechanical type using a thermal expansion body such as a wax element is used. An electric type using a thermistor or the like may be used. The hot water from the hot water storage tank 22 and the water from the pipe 23 merge at the mixing valve 24, for example, about 20 to 40 ° C. and flow downstream. For example, even normal temperature water can flow downstream through the mixing valve 24.

  The pipe 25 is provided downstream of the mixing valve 24 and merges with the water supply pipe 12 at the merge point P2. Hot water (water) from the mixing valve 24 is guided to the hot water outlet 52 through the pipe 25.

  The hot water side electromagnetic valve 21 is an electromagnetic valve for discharging hot water from the hot water storage tank 22. That is, the hot water side electromagnetic valve 21 is an electromagnetic valve that opens and closes the hot water supply passage 20, and water flows into the hot water supply passage 20 when the hot water side electromagnetic valve 21 is opened. The inflowed water is appropriately made hot water and flows from the hot water outlet 52 to the discharge unit 80 and discharged. As the hot water side solenoid valve 21, for example, a latch type solenoid valve is used.

FIG. 3 is a block diagram illustrating an electric water heater according to the embodiment.
The electric water heater 100 further includes a control unit 30, an abnormality detection unit 31, and a storage device 32.
The control unit 30 is electrically connected to each of the sensor 82, the changeover switch 84, the water discharge switch 85, the water side solenoid valve 11, the hot water side solenoid valve 21, the abnormality detection unit 31, and the storage device 32. The control unit 30 may be connected to a heating unit (not shown) of the hot water storage tank 22. The control unit 30 is a control circuit including, for example, an IC element, and controls operations of the sensor 82, the water side solenoid valve 11, the hot water side solenoid valve 21, the abnormality detection unit 31, the storage device 32, the heating unit, and the like.

  The sensor 82 detects an object (for example, a user's hand) in the vicinity of the discharge unit 80. As such a sensor 82, for example, an infrared sensor can be used. The sensor 82 transmits infrared light and receives infrared light reflected by the object. The sensor 82 is not limited to the infrared type, and may be a radio wave type, for example.

  The sensor 82 outputs a signal representing the infrared light reception result (object detection result) to the control unit 30. The control unit 30 determines the presence / absence of an object based on the signal output from the sensor 82. The control unit 30 drives the water side solenoid valve 11 and the hot water side solenoid valve 21 based on the determination result. That is, the control unit 30 controls the opening and closing of the water side solenoid valve 11 and the opening and closing of the hot water side solenoid valve 21.

  When the user puts his hand under the discharge unit 80 or the like, the hand is detected, and the control unit 30 opens either the water-side electromagnetic valve 11 or the hot water-side electromagnetic valve 21, and opens water or hot water from the discharge unit 80. Is discharged. The discharge of water or hot water is continued while the user puts out his hand, that is, while the presence of the hand is detected. When the user releases his / her hand from below the discharge unit 80 and the object is no longer detected, the control unit 30 closes the opened solenoid valve (either the water-side solenoid valve 11 or the hot water-side solenoid valve 21). Then, the discharge of water or hot water from the discharge unit 80 is stopped.

  The changeover switch 84 is a switch that is provided in the vicinity of the discharge unit 80 and switches discharge of hot water. That is, the changeover switch 84 is a switch for switching between a state in which the water side solenoid valve 11 is opened and a state in which the hot water side solenoid valve 21 is opened. When the user operates (presses) the changeover switch 84, a signal is output from the changeover switch 84 to the control unit 30. The control unit 30 drives the water side solenoid valve 11 and the hot water side solenoid valve 21 based on this signal. For example, when the user operates the changeover switch 84, the control unit 30 closes the water side electromagnetic valve 11 and opens the hot water side electromagnetic valve 21, or closes the hot water side electromagnetic valve 21 and opens the water side electromagnetic valve 11.

  The water discharge switch 85 is provided near the discharge unit 80 and is a switch for instructing discharge and stop of water. When the user operates the water discharge switch 85 while both the water side electromagnetic valve 11 and the hot water side electromagnetic valve 21 are closed, a signal is output from the water discharge switch 85. The control unit 30 opens the water side electromagnetic valve 11 based on this signal. Thereafter, when the user operates the water discharge switch 85 again, a signal is output from the water discharge switch 85. Based on this signal, the control unit 30 closes the opened electromagnetic valve.

  The electric water heater 100 (the control unit 30, the water side solenoid valve 11, the hot water side solenoid valve 21, the sensor 82, the changeover switch 84, the water discharge switch 85, the heating unit of the hot water storage tank 22, etc.) is usually supplied from a commercial power source. It operates with power. However, when the commercial power supply is abnormal, for example, during a power failure, it operates with an emergency power supply. The emergency power source is, for example, a power source provided in a facility (building) where the electric water heater 100 is provided. The abnormality detection unit 31 detects such a power supply abnormality, for example, a power failure of a commercial power supply. A specific example of the abnormality detection unit 31 will be described later with reference to FIGS.

  The control unit 30 executes the emergency mode when the power supply is abnormal, and executes the normal mode at other normal times. The operation of the electric water heater 100 described above with reference to FIGS. 2 and 3 is an operation in the normal mode. When the emergency power supply is used when the power supply is abnormal, the abnormality detection unit 31 outputs a signal indicating the power supply abnormality to the control unit 30. The controller 30 executes the emergency mode based on the signal.

  The storage device (storage means) 32 stores the length and number of times that the hot water side solenoid valve 21 is opened and the length and number of times that the water side solenoid valve 11 is opened. As the storage device 32, for example, a semiconductor storage device such as an EEPROM or a flash memory can be used.

Next, with reference to FIG.4 and FIG.5, operation | movement of the electric water heater 100 in emergency mode is demonstrated.
FIG. 4 is a flowchart illustrating the operation of the electric water heater according to the embodiment.
As illustrated in FIG. 4, when the abnormality of the power source is not detected by the abnormality detection unit 31 (step S101: No), the control unit 30 executes the normal mode (step S102).
When the abnormality of the power source is detected by the abnormality detection unit 31 (step S101: Yes), the control unit 30 executes the emergency mode (steps S103 to S114). The emergency mode is an operation mode in which hot water in the hot water storage tank 22 is preferentially used compared to water.

  In the emergency mode, the control unit 30 turns off the heating unit of the hot water storage tank 22 (step S103). Since the emergency power supply may be limited, power consumption is suppressed by turning off the heating unit and not heating the water in the hot water storage tank 22.

  Thereafter, the control unit 30 is set to the hot water discharge mode (step S104). The hot water discharge mode is a mode in which the hot water solenoid valve 21 is opened when the sensor 82 detects an object (a user's hand). That is, the control unit 30 preferentially opens the hot water side solenoid valve 21 compared to the water side solenoid valve 11 when the power supply is abnormal.

  When the heating unit of the hot water storage tank 22 is turned off, the temperature of the hot water in the hot water storage tank 22 decreases with time. As a result, bacteria may easily propagate in the hot water storage tank 22. For example, Legionella bacteria are likely to grow at about 40 ° C. On the other hand, in the embodiment, the hot water solenoid valve 21 is opened preferentially when the power supply is abnormal, so that the water (hot water) in the hot water storage tank 22 is used preferentially over the water passing through the water supply pipe 12. To do. By opening the hot water side solenoid valve 21, hot water heated in the hot water storage tank 22 before the abnormality of the power source flows out of the hot water storage tank 22, and normal temperature water flows into the hot water storage tank 22. Thereby, it can suppress that hot water continues to remain in the hot water storage tank 22. Since the hot water can be used up at an early stage, the propagation of bacteria in the hot water storage tank 22 can be suppressed, and hygiene can be ensured. Further, it is possible to ensure the comfort of the user who wants to use hot water even when the power supply is abnormal.

  However, during the execution of the emergency mode, after the discharge of hot water in the hot water storage tank 22 has ended and a predetermined time or more has elapsed since the previous opening operation of the hot water side solenoid valve 21 (step S105: Yes). ), The control unit 30 is set to the water discharge mode (step S106). The water spouting mode is a mode in which only the water-side electromagnetic valve 11 is opened when the sensor 82 detects an object.

  That is, during execution of the emergency mode, when a predetermined time or more has elapsed from the time when the hot water side solenoid valve 21 was last opened (or when the hot water side solenoid valve 21 was last closed), the control unit 30 The solenoid valve 21 is not opened.

  On the other hand, when the predetermined time has not elapsed since the previous opening operation of the hot water side solenoid valve 21 during execution of the emergency mode (step S105: No), the control unit 30 gives priority to the hot water side solenoid valve 21. The water (hot water) in the hot water storage tank 22 is preferentially used.

  When the faucet device 200 is not used for a long time, the same water continues to stay in the hot water storage tank 22 and the water supply pipe 12 during that time. At this time, since the capacity of the hot water storage tank 22 is larger than the capacity of the water supply pipe 12, bacteria are more likely to propagate in the hot water storage tank 22 than in the water supply pipe 12. Therefore, in the embodiment, when a long time (predetermined time) has elapsed since the opening operation of the hot water side solenoid valve 21 as in steps S105 and S106, the bacteria are removed by opening only the water side solenoid valve 11. The hot water (water) in the hot water storage tank 22 which may be breeding is not discharged. If the predetermined time has not elapsed, the hot water side solenoid valve 21 is preferentially opened, so that the water in the hot water storage tank is replaced to suppress the growth of bacteria. Thereby, hygiene can be ensured.

  The predetermined time in step S105 is appropriately determined in consideration of the capacity of the hot water storage tank 22, the speed at which the temperature of the hot water in the hot water storage tank 22 decreases, and the like. This predetermined time is, for example, about 12 to 72 hours. The previous opening time of the hot water side solenoid valve 21 is stored in the storage device 32, for example.

  Further, the capacity of water (hot water) flowing out of the hot water storage tank 22 when the power supply is abnormal can be estimated from the time when the hot water side solenoid valve 21 stored in the storage device 32 is opened. That is, the amount of water flowing out of the hot water storage tank 22 is calculated based on the flow rate when the hot water side solenoid valve 21 is opened and the accumulated time when the hot water side solenoid valve 21 is open when the power supply is abnormal. Can do.

  When it is determined No in step S105 and the accumulated time when the hot water side solenoid valve 21 is opened when the power supply is abnormal is equal to or shorter than the predetermined time (step S107: No), the control unit 30 remains in the hot water discharge mode. (Step S109).

  The predetermined time in step S107 is, for example, the time required for water exceeding the capacity in the hot water storage tank 22 to flow out of the hot water storage tank 22. That is, when it is determined No in step S107, the hot water heated before the abnormality of the power source remains in the hot water storage tank 22. Therefore, the hot water remaining in the hot water storage tank 22 is discharged by the hot water spouting mode that preferentially opens the hot water side solenoid valve 21, thereby suppressing the hot water from remaining in the hot water storage tank 22. 22 to suppress the growth of bacteria.

  When the accumulated time when the hot water side solenoid valve 21 is open at the time of power failure is longer than the predetermined time (step S107: Yes), the control unit 30 is set to the alternate water discharge mode (step S108).

  The alternate water discharge mode is a mode in which, when water or hot water is discharged a plurality of times, the frequency at which the hot water side electromagnetic valve 21 is opened is equal to or higher than the frequency at which the water side electromagnetic valve 11 is opened. For example, in the alternate water discharge mode, every time the sensor 82 detects an object, the electromagnetic valve to be opened is switched. Alternatively, each time the hot water side solenoid valve 21 is opened a predetermined number of times, the water side solenoid valve 11 may be opened only once. Alternatively, based on the data stored in the storage device 32, the water side solenoid valve 11 and the hot water side are set such that the time when the hot water side solenoid valve 21 is open is longer than the time when the water side solenoid valve 11 is open. The opening / closing of the electromagnetic valve 21 may be controlled.

  If only the hot water side solenoid valve 21 is opened, the same water stays in the water supply pipe 12 for a long time, and it is also conceivable that bacteria propagate in the water supply pipe 12. Therefore, when the accumulated time that the hot water side solenoid valve 21 is opened is longer than the predetermined time as in step S108, the control unit 30 is set to the alternate water discharge mode. Thereby, the water in the water supply pipe 12 is replaced by opening the water-side solenoid valve 11 while ensuring the comfort and hygiene of the user by preferentially using the hot water in the hot water storage tank 22 to supply water. Proliferation of bacteria in the tube 12 can be suppressed.

  As described above with respect to steps S107 to S109, the control unit 30 controls the opening and closing of the water side solenoid valve 11 and the hot water side solenoid valve 21 based on the storage in the storage device 32 during execution of the emergency mode. The amount of hot water remaining in the hot water storage tank 22 from the start of execution of the emergency mode can be estimated from the time when the hot water side solenoid valve 21 is opened. For this reason, by using the hot water in the tank preferentially based on this time, it is possible to suppress the growth of bacteria and ensure hygiene.

  After the control unit 30 is set to any one of the water discharge mode, the hot water discharge mode, and the alternate water discharge mode, when the sensor 82 detects an object (step S110: Yes), the control unit 30 includes the water-side solenoid valve. 11 or the hot water side solenoid valve 21 is opened (water discharge control) (step S111). Then, while the sensor 82 continues to detect the object, the discharge of water or hot water is continued (step S112: No). When the sensor no longer detects the object, the control unit 30 closes the opened electromagnetic valve (step S112: Yes).

  And the control part 30 calculates the time when the water side solenoid valve 11 opened in step S111, S112, and the time when the hot water side solenoid valve 21 opened in step S111, S112 (step S113). The calculated time is stored in the storage device 32.

  Thereafter, when the power supply recovers from the abnormality (step S114: Yes), the control unit 30 ends the emergency mode and executes the normal mode. When the power supply has not recovered from the abnormality (step S114: No), the control unit 30 continues to execute the emergency mode.

FIG. 5 is a flowchart illustrating the operation of the electric water heater according to the embodiment.
FIG. 5 is a diagram illustrating water discharge control by the control unit 30 in the emergency mode.
In the emergency mode, the changeover switch 84 or the water discharge switch 85 has a function as an operation unit for switching between a water discharge mode for operating the water side electromagnetic valve 11 and a hot water discharge mode for operating the hot water side electromagnetic valve 21. For example, when the user operates the changeover switch 84 or the water discharge switch 85 in the emergency mode (step S201: Yes), the control unit 30 is set to the water discharge mode when determining that the operation unit is operated ( Step S202, Step S203: Yes). And the control part 30 drives and opens the water side solenoid valve 11 (step S206). For example, even if the control unit 30 is set to the hot water discharge mode immediately before the water discharge switch 85 is operated, when the water discharge switch 85 is operated, the control unit 30 is switched to the water discharge mode. A user who wants to use water instead of hot water can use water by operating the changeover switch 84 or the water discharge switch 85. Thereby, a user's usability can be improved.

  When the water spouting switch 85 is not operated and the sensor 82 detects an object as in step S110 described with reference to FIG. 4 (step S201: No), the control unit 30 is set to the water spouting mode ( In step S203: Yes), the control unit 30 opens the water-side electromagnetic valve 11 (step S206).

  When the control unit 30 is set to the hot water discharge mode (step S204: Yes), the control unit 30 opens the hot water side solenoid valve 21 (step S207).

  When the control unit 30 is set to the alternate water discharge mode (step S204: No), when the water-side solenoid valve 11 is opened at the time of the previous water discharge (during hot water discharge or water discharge) (step S205: Yes), the control unit 30 opens the hot water side solenoid valve 21 (step S207).

  When the control unit 30 is set to the alternate water discharge mode (step S204: No), when the hot water side solenoid valve 21 is opened at the previous water discharge (step S205: No), the control unit 30 is The electromagnetic valve 11 is opened (step S206).

  In addition, when the water side solenoid valve 11 and the hot water side solenoid valve 21 are closed, the control unit 30 determines which of the water side solenoid valve 11 and the hot water side solenoid valve 21 is to be opened next. Specifically, in steps S203, S204, and S205 before steps S206 and S207, it is determined which of the water side solenoid valve 11 and the hot water side solenoid valve 21 is to be opened.

  In other words, when the hot water side electromagnetic valve 21 is open, the control unit 30 does not switch from the state where the hot water side electromagnetic valve 21 is open to the state where the water side electromagnetic valve 11 is open. Further, when the water side solenoid valve 11 is open, the control unit 30 does not switch from the state in which the water side solenoid valve 11 is open to the state in which the hot water side solenoid valve 21 is open. That is, when water or hot water is being discharged, the solenoid valve that is opened unintentionally by the user is not switched and the water temperature does not change suddenly, so that it is possible to prevent the user from feeling uncomfortable.

Next, the commercial power supply, emergency power supply, and abnormality detection unit 31 will be described with reference to FIGS.
The emergency power source is, for example, an inverter power source (a DC power source connected via an inverter) that is turned on as a backup when a commercial power source cannot be used due to a power failure or the like. The abnormality detection unit 31 is a circuit that detects a power supply abnormality by determining whether the power supplied to the electric water heater 100 is a commercial power supply or an emergency power supply such as an inverter power supply.

FIG. 6 is a flowchart illustrating the operation of the abnormality detection unit according to the embodiment.
6 corresponds to step S101 described with reference to FIG. This process is performed, for example, when the electric water heater 100 is activated. Here, starting means turning on the electric water heater 100 and starting the operation. As for the situation of turning on the power, when the electric water heater 100 is attached to the faucet device 200 and then the commercial power is connected and turned on, the power is turned off and then turned on again. For example, when the commercial power supply cannot be used due to a power failure and the emergency power is turned on.

  In this example, the abnormality detection unit 31 determines whether the supplied power source is a commercial power source or an emergency power source based on the waveform of the power source voltage. Specifically, the abnormality detection unit 31 determines the power source based on three criteria (the frequency of the power source, whether the power source waveform is a sine wave, or the peak value of the power source).

FIG. 7 is a graph illustrating the voltage waveform of the commercial power supply.
FIG. 8 is a graph illustrating the voltage waveform of the emergency power supply. In this example, the emergency power supply is an inverter power supply.
Each of the horizontal axis in FIG. 7 and the horizontal axis in FIG. 8 represents time. Each of the vertical axis | shaft of FIG. 7 and the vertical axis | shaft of FIG. 8 represents a voltage.
The frequency of the voltage of the commercial power source shown in FIG. 7 is 50 Hz in eastern Japan and 60 Hz in western Japan. On the other hand, the frequency of the voltage of the inverter power supply depends on the configuration of the inverter circuit that performs DC-AC conversion. In the example of the waveform shown in FIG. 8, the frequency is 55 Hz. Thereby, for example, this inverter power supply can be used in an area where the frequency of the commercial power supply is 50 Hz or 60 Hz.
Therefore, when the frequency of the power supply voltage is 50 Hz or 60 Hz, the power supply is likely to be a commercial power supply, and when the frequency of the power supply voltage is neither 50 Hz nor 60 Hz (for example, an intermediate value between 50 Hz and 60 Hz). There is a high probability that the power source is an emergency power source.

Further, the voltage waveform of the commercial power source shown in FIG. 7 is a sine wave. On the other hand, generally, the waveform of the voltage converted from the DC power source by the inverter that performs DC-AC conversion is not a sine wave but a rectangular wave as shown in FIG. Although the shape of this rectangular wave also depends on the configuration of the inverter circuit, an inverter circuit that generates a rectangular wave having a shape close to a sine wave to such an extent that a device operating with a commercial power supply can be used is generally used. .
Therefore, if the power supply voltage waveform is a sine wave, the power supply is likely to be a commercial power supply. If the power supply voltage waveform is a rectangular wave other than a sine wave, the power supply may be an emergency power supply. Is expensive. For example, the rising and falling slopes of the rectangular wave voltage are steeper than the rising and falling slopes of the sine wave voltage. That is, for example, when the voltage rises or falls, the change in the rectangular wave voltage within the predetermined time is larger than the change in the rectangular wave voltage within the predetermined time.

Moreover, the peak values of the commercial power source shown in FIG. 7 are + 141V and −141V. On the other hand, the absolute value of the peak value of the power supply voltage after DC-AC conversion by a general inverter circuit is smaller than 141V.
Therefore, when the absolute value of the peak value of the power supply voltage is 141 V, the power supply is likely to be a commercial power supply. When the absolute value of the peak value of the power supply voltage is other than 141 V, the power supply is an emergency power supply. Probability is high. In the determination of the power source, the peak value of either + 141V or −141V may be used as a reference.

  In the example illustrated in FIG. 6, the abnormality detection unit 31 determines the power source based on the above three criteria and detects an abnormality. When the electric water heater 100 is activated, the abnormality detection unit 31 starts an abnormality detection process (step S301). The abnormality detection unit 31 first determines whether or not the frequency of the power supply voltage is 50 Hz or 60 Hz (step S302). When it is determined that the frequency is neither 50 Hz nor 60 Hz (step S302: No), the abnormality detection unit 31 determines that the power source is an emergency power source (step S306). When it is determined that the frequency of the power supply voltage is 50 Hz or 60 Hz (step S302: Yes), the abnormality detection unit 31 determines whether the waveform is a sine wave (step S303).

  For example, the abnormality detection unit 31 determines whether or not the waveform is a sine wave based on a change in voltage within a predetermined time when the voltage rises or falls. When it is determined that the voltage waveform is not a sine wave (step S303: No), the abnormality detection unit 31 determines that the power supply is an emergency power supply (step S306). When it is determined that the voltage waveform is a sine wave (step S303: Yes), the abnormality detection unit 31 then determines whether or not the peak value of the power supply voltage is 141 V (step S304).

  When it is determined that the peak value of the power supply voltage is not 141 V (step S304: No), the abnormality detection unit 31 determines that the power supply is an emergency power supply (step S306). When it is determined that the peak value of the power supply voltage is 141 V (step S304: Yes), the abnormality detection unit 31 determines that the power supply voltage is a commercial power supply (step S305).

  As described above, the abnormality detection unit 31 ends the abnormality detection process for the power supply (step S307). That is, the abnormality detection unit 31 detects that the power supply is normal when the supplied power is a commercial power supply, and detects that the power supply is abnormal when the supplied power is an emergency power supply. To do. The detection result is output to the control unit 30.

The embodiment of the present invention has been described above. However, the present invention is not limited to these descriptions. As long as the features of the present invention are provided, those skilled in the art appropriately modified the design of the above-described embodiments are also included in the scope of the present invention. For example, the shape, size, material, arrangement, installation form, and the like of each element included in the electric water heater 100 are not limited to those illustrated, but can be changed as appropriate.
Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

  DESCRIPTION OF SYMBOLS 10 Water supply flow path, 11 Water side solenoid valve, 12 Water supply pipe, 20 Hot water supply flow path, 21 Hot water side solenoid valve, 22 Hot water storage tank, 23 pipe, 24 Mixing valve, 25 pipe, 30 Control part, 31 Abnormality detection part, 32 Storage device, 51 Water supply port, 52 Hot water outlet, 71 Water supply source, 72 tube, 73 tube, 80 Discharge unit, 82 Sensor, 84 Changeover switch, 85 Water discharge switch, 86 Bowl, 100 Electric water heater, 200 Water faucet device

Claims (6)

A water pipe,
A hot water storage tank that heats the water into hot water,
A hot water side solenoid valve for discharging hot water from the hot water storage tank;
A water-side solenoid valve for discharging water from the water supply pipe;
A control unit for controlling opening and closing of the water side solenoid valve and the hot water side solenoid valve;
An anomaly detector that detects an anomaly in the power supply;
With
The electric water heater according to claim 1, wherein the control unit executes an emergency mode in which the hot water side solenoid valve is preferentially opened compared to the water side solenoid valve when the power source is abnormal based on a signal from the abnormality detection unit. A storage device for storing a time when the hot water side solenoid valve is opened;
The said control part controls opening and closing of the said water side solenoid valve and the said hot water side solenoid valve based on the said time which the said memory | storage device memorize | stores during execution of the said emergency mode. Electric water heater.   The control unit opens the water side solenoid valve and the hot water side solenoid valve during execution of the emergency mode, and sets the frequency of opening of the hot water side solenoid valve to be higher than the frequency of opening of the water side solenoid valve. The electric water heater according to claim 1 or 2. An operation unit that switches between a water discharge mode for operating the water side solenoid valve and a hot water discharge mode for operating the hot water side solenoid valve;
The electric water heater according to any one of claims 1 to 3, wherein the control unit enters the water discharge mode when it is determined that the operation unit is operated during execution of the emergency mode.   The controller, after execution of the emergency mode, after discharge of hot water in the hot water storage tank and after a predetermined time or more has elapsed since the previous opening operation of the hot water side solenoid valve, The electric water heater according to any one of claims 1 to 4, wherein only the water side solenoid valve is opened.   The said control part judges whether the said hot water side solenoid valve or the said water side solenoid valve is opened next, when the said hot water side solenoid valve and the said water side solenoid valve are closed. The electric water heater as described in any one of 1-5.