JP2021148391A - Water leakage determination device for hot water supply system - Google Patents

Abstract

To provide a water leakage determination device for a hot water supply system capable of enhancing water leakage determination accuracy in various use environments.SOLUTION: A water leakage determination device 100 for a hot water supply system X including a water heater 1 with water supply piping 21, hot water supply piping 23, a heater 2 and a control section 3 includes: a water temperature measurement section 41 measuring a temperature of water flowing in the water supply piping 21; an atmospheric temperature measurement section 42 measuring a temperature of inside air of the water heater 1; and a determination section 12 executing a water leakage determination in the hot water supply system X. When the water heater 1 is in a waiting state from stop of hot water supply to start of the hot water supply and the control section 3 executes control for raising the temperature of the inside air of the water heater 1, the determination section 12 executes the water leakage determination on the basis of the measurement value obtained by the water temperature measurement section 41 and the measurement value obtained by the atmospheric temperature measurement section 42.SELECTED DRAWING: Figure 1

Description

The present invention relates to a water leakage determination device for a hot water supply system having a water heater.

Generally, a hot water supply system that supplies hot water to a hot water consuming device provided in a kitchen, bathroom, or the like heats water flowing in from a water supply pipe with a water heater to generate hot water. That is, the hot water supply system is provided with a water heater equipped with a water supply pipe through which water flows, a hot water supply pipe through which hot water flows, and a heater that heats the water flowing in from the water supply pipe and discharges the hot water to the hot water supply pipe. Has been done. In this hot water supply system, water leaks from the joints of the pipes, water leaks due to corrosion of the pipes, water leaks due to malfunction of the valve that controls hot water supply, and the like may occur.

Patent Document 1 discloses a water leakage determination device capable of determining a small amount of water leakage in a hot water supply system. In the invention described in Patent Document 1, when hot water supply is restarted after the hot water supply is stopped, cold water is usually supplied to the water supply pipe heated by the atmospheric temperature inside the water heater to lower the water temperature, but water leakage occurs. When is occurring, the flow of water in the water supply pipe is not stopped, so we are paying attention to the fact that the amount of fluctuation in water temperature is small. Therefore, in the water leakage determination device described in Patent Document 1, after starting hot water supply, the temperature difference between the water temperature of the water supply pipe and the ambient temperature outside the water heater is equal to or more than a predetermined temperature difference, and the water temperature in the water supply pipe It is determined that a water leak has occurred when the fluctuation amount of is less than a predetermined value.

JP-A-2017-172934

However, in the water leakage determination device described in Patent Document 1, if a sufficient hot water supply time for heating the water supply pipe is not secured, the fluctuation amount of the water temperature in the water supply pipe becomes small even if there is no water leakage, and until the next hot water supply. When the interval between the two is short, the amount of fluctuation of the water temperature in the water supply pipe becomes large even if there is a water leak, so that the accuracy of the water leak determination may decrease.

Therefore, there is a demand for a water leakage determination device for a hot water supply system that can improve the accuracy of water leakage determination in various usage environments.

The characteristic configuration of the water leakage determination device of the hot water supply system according to the present invention is that the water supply pipe through which water flows, the hot water supply pipe through which hot water flows, and the water flowing in from the water supply pipe are heated and the hot water is discharged to the hot water supply pipe. A water leakage determination device for a hot water supply system having a water heater including a heater for controlling operation and a control unit for controlling operation, the water temperature measuring unit for measuring the temperature of water flowing through the water supply pipe, and the water heater. It is provided with an atmosphere temperature measuring unit that measures the temperature of the internal air of the water heater and a determination unit that executes a water leakage determination of the hot water supply system. When the control unit is in a standby state and the control unit executes a control to raise the temperature of the internal air of the water heater, the water leak occurs based on the measured values of the water temperature measuring unit and the atmospheric temperature measuring unit. The point is to execute the judgment.

In this configuration, in the standby state when hot water supply is stopped, control to raise the temperature of the internal air of the water heater is executed, and water leakage judgment is executed based on the measured value of the water temperature measuring unit and the measured value of the atmospheric temperature measuring unit. doing. In other words, regardless of how often the water heater is used, the inside of the water heater is forcibly heated while the hot water supply is stopped. Therefore, if there is no water leakage in the hot water supply system, the ambient temperature inside the water heater will be adjusted. It is possible to raise the temperature of the water supply pipe accordingly.

On the other hand, when a water leak occurs in the hot water supply system, the water temperature of the water supply pipe does not follow the atmospheric temperature inside the water heater because cold water is constantly circulated in the water supply pipe. Therefore, even when the inside of the water heater is forcibly heated while the hot water supply is stopped, the water temperature of the water supply pipe does not approach the atmospheric temperature inside the water heater, so that the water leakage determination is accurate.

As described above, it has been possible to provide a water leakage determination device for a hot water supply system capable of improving the accuracy of water leakage determination regardless of the frequency of use of the water heater.

Another feature configuration is that the determination unit determines that there is no water leakage when the absolute value of the difference between the measurement value of the water temperature measurement unit and the measurement value of the atmosphere temperature measurement unit is equal to or less than a predetermined temperature. ..

If there is no water leakage in the hot water supply system when the control to raise the temperature of the internal air of the water heater is executed in the standby state while the hot water supply is stopped, the water temperature of the water supply pipe becomes the atmospheric temperature inside the water heater. Follow. Therefore, if it is determined that there is no water leakage when the absolute value of the difference between the measured value of the water temperature measuring unit and the measured value of the atmosphere temperature measuring unit is equal to or less than the predetermined temperature as in this configuration, the water leakage determination is accurate. It will be something like that.

The characteristic configuration of the water leakage determination device according to the present invention is a water supply pipe through which water flows, a hot water supply pipe through which hot water flows, and a heater that heats water flowing in from the water supply pipe and discharges hot water to the hot water supply pipe. It is a water leakage determination device of a hot water supply system having a water heater equipped with the above, and is a water temperature measuring unit for measuring the temperature of water flowing through the water supply pipe and a hot water temperature for measuring the temperature of hot water flowing through the hot water supply pipe. The determination unit includes a measurement unit, an atmosphere temperature measurement unit that measures the temperature of the internal air of the water heater, and a determination unit that executes water leakage determination of the hot water supply system. The point is that the water leakage determination is executed based on the measured values of the water temperature measuring unit or the hot water temperature measuring unit and the measured values of the atmospheric temperature measuring unit.

If there is no water leakage in the hot water supply system after the hot water supply is stopped, the water temperature of the water supply pipe in the water heater and the water temperature of the hot water supply pipe converge to the atmospheric temperature inside the water heater. On the other hand, if water leakage occurs in the hot water supply system after the hot water supply is stopped, cold water is constantly flowing through the water supply pipe. Therefore, after the hot water supply is stopped, the water temperature of the water supply pipe and the water temperature of the hot water supply pipe are inside the water heater. It does not follow the ambient temperature of the water heater and converges on the temperature of the tap water outside the water heater.

Therefore, in this configuration, after the hot water supply is stopped when the measured value of the flow rate measuring unit becomes from the predetermined value or more to less than the predetermined value, the measured value of the water temperature measuring unit or the hot water temperature measuring unit and the measured value of the atmospheric temperature measuring unit are used. Perform a water leak check. That is, if the water leakage determination is executed based on the water temperature of the water supply pipe or the hot water temperature of the hot water supply pipe whose temperature change behavior differs depending on the presence or absence of water leakage in the hot water supply system, the water leakage determination becomes accurate.

As described above, since the water leak determination is executed after the hot water supply is stopped, it is possible to provide the water leak determination device of the hot water supply system capable of improving the water leakage determination accuracy regardless of the frequency of use of the water heater.

Another characteristic configuration is that the determination unit has no water leakage if the absolute value of the difference between the measurement value of the water temperature measurement unit or the hot water temperature measurement unit and the measurement value of the atmosphere temperature measurement unit is equal to or less than a predetermined temperature. It is at the point of judging.

If there is no water leakage in the hot water supply system after the hot water supply is stopped, the water temperature of the water supply pipe in the water heater and the water temperature of the hot water supply pipe converge to the atmospheric temperature inside the water heater. Therefore, if it is determined that there is no water leakage if the absolute value of the difference between the measured value of the water temperature measuring unit or the hot water temperature measuring unit and the measured value of the atmospheric temperature measuring unit is equal to or less than the predetermined temperature as in this configuration, then water The leak judgment is accurate.

Another characteristic configuration further includes a tap water temperature measuring unit that measures the temperature of water flowing through a water pipe connected to the water supply pipe outside the water dispenser, and the determination unit is the water temperature measuring unit or the hot water. When the measured value of the temperature measuring unit is closer to the measured value of the tap water temperature measuring unit than the measured value of the atmospheric temperature measuring unit, it is determined that there is a water leak.

If there is a water leak in the hot water supply system after the hot water supply is stopped, cold water is constantly flowing through the water supply pipe. It does not follow the internal atmospheric temperature and becomes close to the tap water temperature of the water pipe. Therefore, as in this configuration, when the measured value of the water temperature measuring unit or the hot water temperature measuring unit is closer to the measured value of the tap water temperature measuring unit than the measured value of the atmospheric temperature measuring unit, it is determined that there is a water leak. Then, the water leakage determination becomes accurate.

Another feature configuration is that the determination unit executes the water leakage determination based on the rate of change of the measured value of the water temperature measurement unit.

If there is no water leak in the hot water supply system after the hot water supply is stopped, the water temperature of the water supply pipe in the water heater converges to the atmospheric temperature inside the water heater, and if there is a water leak in the hot water supply system. Since cold water is constantly flowing through the water supply pipe, the water temperature of the water supply pipe in the water heater hardly changes. Therefore, based on the rate of change of the measured value of the water temperature measuring unit as in this configuration, the water leakage determination becomes accurate.

Another characteristic configuration further includes a flow rate measuring unit that measures the flow rate of water flowing through the water supply pipe, and the determination unit determines the water leakage when the measured value of the flow rate measuring unit is less than a predetermined value. It is in the point of execution.

In this configuration, it is possible to reliably detect the standby state or the hot water supply stop state of the water heater that executes the water leakage determination.

Another characteristic configuration further includes a learning unit that learns a hot water supply period in which the measured value of the flow rate measuring unit is equal to or greater than the predetermined value, and the determination unit further includes the water based on the hot water supply period learned by the learning unit. The point is to execute the leak judgment.

If the water leak determination is executed based on the hot water supply period learned by the learning unit as in this configuration, the water leak determination can be executed when the water heater is used infrequently, so that the hot water supply is started again during the water leak determination. , It is possible to prevent the inconvenience that the water leakage determination accuracy is lowered.

Another feature configuration is that the determination unit stops the execution of the water leakage determination when the measurement value of the flow rate measurement unit becomes the predetermined value or more.

As in this configuration, if the execution of the water leak determination is stopped when the measured value of the flow rate measuring unit exceeds the predetermined value, even if hot water supply is started during the water leak determination, the water leak is erroneously determined. Can be prevented.

Another feature configuration is that it further includes a storage unit that stores the result of the water leakage determination by the determination unit, and the determination unit changes the execution frequency of the water leakage determination based on the result.

If the execution frequency of the water leak judgment is changed based on the result of the water leak judgment as in this configuration, it is possible to reduce the energy consumption due to the unnecessary water leak judgment when there is no water leak, and there is a water leak. In that case, the reliability of the water leakage determination can be increased by increasing the determination frequency.

Another feature configuration further includes a notification unit that notifies the result of the water leakage determination by the determination unit, and the notification unit is configured to operate when the determination unit determines that there is a water leak. There is a point.

If the notification unit is activated when there is a water leak as in this configuration, the user can know the water leak information, and the business operator can take prompt measures such as water leak prevention measures.

It is a schematic diagram of a hot water supply system. It is a block diagram of a water leakage determination device. It is a water leakage determination flow chart which concerns on 1st Embodiment. It is a figure which shows the example of the water temperature behavior which concerns on 1st Embodiment. It is a water leakage determination flow chart which concerns on 2nd Embodiment. It is a figure which shows the example of the hot water temperature behavior which concerns on 2nd Embodiment. It is a figure which shows the learning example of a hot water supply period.

Hereinafter, embodiments of the water leakage determination device of the hot water supply system according to the present invention will be described with reference to the drawings. In the present embodiment, as an example of the water leakage determination device, the water leakage determination device 100 for determining the water leakage of the hot water supply system X having the water heater 1 will be described. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist thereof.

As shown in FIG. 1, the hot water supply system X heats water in the water heater 1 to generate hot water, and supplies this hot water to the hot water consuming device 90 outside the water heater 1. The water leakage determination device 100 in the present embodiment includes water leakage due to damage to the piping system (for example, the portion of reference numeral L in FIG. 1) and the valve of the hot water supply system X, water leakage to the downstream side due to foreign matter biting into the valve, and the like. Determine the presence or absence. The water leak determination device 100 may be a mechanism that functions as a part of the hot water supply function of the water heater 1, or may be a function of a computer provided in a management center that centrally manages the state of the water heater 1. You may take charge of a part.

The water heater 1 is provided with a pipe 20 inside the casing 60, and the pipe 20 is provided with a heat exchanger 2 (an example of a heater) which is a hot water supply heat source. The water heater 1 has a hot water supply function by applying the heat obtained from the combustion flame of a combustion gas such as natural gas supplied from the gas pipe 24 to the water flowing through the pipe 20 by the heat exchanger 2 to obtain hot water. Is a gas water heater that runs.

The water heater 1 in the present embodiment includes a casing 60, a pipe 20 provided in the casing 60 and including a water supply pipe 21 through which water (tap water) from the water pipe W flows and a hot water supply pipe 23 through which hot water flows. A heat exchanger 2 provided between the water supply pipe 21 and the hot water supply pipe 23, and a flow rate measuring unit that measures the flow rate of hot water supplied from the hot water supply pipe 23 by heating the water supplied from the water supply pipe 21 with the heat exchanger 2. It is equipped with 51. The water leak determination device 100 determines the water leak of the hot water supply system X having the water heater 1.

Further, the water heater 1 has a control unit 3 for controlling its operation, and also includes a mechanism, a functional unit, and the like used for a generally known water heater. The control unit 3 is composed of software centered on a CPU and memory that execute various processes, or collaboration between hardware and software.

The casing 60 is filled with air, and is provided with an atmosphere temperature measuring unit 42 having a thermometer such as a temperature sensor for measuring the temperature of the air. The heater H is composed of an electric heater or the like for preventing the water flowing through the pipe 20 from freezing. The atmospheric temperature measuring unit 42 includes, for example, a thermocouple or a thermistor (hereinafter referred to as “thermocouple or the like”) as a temperature sensor, and the control unit 3 or the water leakage determination is obtained from information related to the temperature detected by the thermocouple or the like. Output to device 100.

The heat exchanger 2 is a member that heats the water flowing through the pipe 20 to make hot water, heats the water flowing in from the water supply pipe 21, and discharges the hot water to the hot water supply pipe 23. The heat exchanger 2 gives heat obtained from, for example, a combustion flame of natural gas supplied from the gas pipe 24 to the water flowing through the pipe 20. The amount of heat supplied to the heat exchanger 2 is adjusted by adjusting the opening degree of the gas valve 33 provided in the gas pipe 24. The opening / closing and opening degree of the gas valve 33 are controlled by the control unit 3. The exhaust gas of the combustion gas generated by the combustion of the natural gas is discharged to the outside of the casing 60 through the exhaust pipe 25.

The pipe 20 is housed inside the casing 60 and is a pipe portion for supplying water and hot water. Of the pipes 20, the pipe 20 on the upstream side of the heat exchanger 2 is the water supply pipe 21, and the pipe 20 on the downstream side of the heat exchanger 2 is the hot water supply pipe 23. Therefore, the pipe 20 uses the water supplied from the outside as a water supply source and circulates it to the water supply pipe 21, the heat exchanger 2, and the hot water supply pipe 23 to supply hot water to the hot water consumption device 90.

The pipe 20 is provided with a bypass pipe 22 that connects the water supply pipe 21 to the hot water supply pipe 23 so as to bypass the heat exchanger 2. If necessary, the opening degree of the bypass valve 32 provided in the bypass pipe 22 can be adjusted to adjust the hot water supply temperature of the water heater 1.

The water supply pipe 21 is a pipe portion that receives water from a water pipe W outside the water heater 1 and communicates with the heat exchanger 2. The water pipe W is provided with a tap water temperature measuring unit 7. The water supply pipe 21 is provided with a heater H, a water supply valve 31, a flow rate measuring unit 51, and a water temperature measuring unit 41. The water supply pipe 21 of the present embodiment is provided with a heater H, a water supply valve 31, a flow rate measuring unit 51, and a water temperature measuring unit 41 in this order from upstream to downstream. The hot water supply pipe 23 is a piping unit that communicates with the heat exchanger 2 and supplies hot water supplied from the heat exchanger 2 to the hot water consuming device 90 outside the water heater 1. The hot water supply pipe 23 is provided with a hot water temperature measuring unit 43. The hot water supply pipe 23 may also be provided with the heater H, and the location where the heater H is provided is not particularly limited.

The heater H is composed of an electric heater or the like for preventing the water flowing through the pipe 20 from freezing. The control unit 3 operates the heater H when the temperature measured by the atmosphere temperature measurement unit 42 becomes equal to or lower than the freezing temperature (for example, 0 ° C.). The heater H may be operated based on the measured value of a thermometer (not shown) that measures the ambient temperature of the water heater 1.

The water supply valve 31 is a valve member composed of a ball valve or the like that controls the flow of water in the pipe 20. As the valve member used for the water supply valve 31, a diaphragm valve, a butterfly valve, or the like can also be used. The water supply valve 31 switches between an open state and a closed state according to an instruction from the control unit 3. That is, hot water can be supplied with the water supply valve 31 open. Information related to the open / closed state of the water supply valve 31 is output to the control unit 3.

The flow rate measuring unit 51 has a flow meter that measures the flow rate of hot water supplied through the pipe 20 via the heat exchanger 2. The flow rate measuring unit 51 is composed of, for example, a propeller type flow meter as a flow meter, and outputs information related to the flow rate detected by the flow meter to the control unit 3 and the water leakage determination device 100. The lower limit of the dynamic range of the measurement of the flow rate measuring unit 51 in the present embodiment is set to 2 liters per minute (an example of a predetermined value), and when the hot water supply flow rate flowing through the pipe 20 is less than 2 liters per minute, Output zero.

The tap water temperature measuring unit 7 has a thermometer such as a temperature sensor that measures the temperature of tap water flowing through the water pipe W. Further, the water temperature measuring unit 41 has a thermometer such as a temperature sensor that measures the temperature of the water flowing through the water supply pipe 21. The tap water temperature measuring unit 7 is provided outside the casing 60 (water heater 1), and the water temperature measuring unit 41 is provided inside the casing 60 (water heater 1). The tap water temperature measuring unit 7 and the water temperature measuring unit 41 include, for example, a thermocouple or the like as a temperature sensor, and output information related to the temperature detected by the thermoelectric pair or the like to the control unit 3 or the water leakage determination device 100.

The water supply pipe 21 in the present embodiment includes a heat transfer unit 44 in the vicinity of the temperature sensor of the water temperature measurement unit 41. The heat transfer unit 44 exerts a function of bringing the temperature of the air in the casing 60 (atmospheric temperature) close to the temperature of the water in the water supply pipe 21 in the vicinity of the temperature sensor of the water temperature measuring unit 41. Specifically, heat is transferred between the air in the casing 60 and the water in the water supply pipe 21 so that the water temperature of the water supply pipe 21 near the temperature sensor of the water temperature measuring unit 41 approaches the atmospheric temperature in the casing 60. Heat is exchanged through the unit 44. The heat transfer unit 44 is composed of heat transfer fins or the like having a plurality of metal plates erected on the water supply pipe 21 near the temperature sensor of the water temperature measurement unit 41. The heat transfer unit 44 may be omitted.

The hot water temperature measuring unit 43 has a thermometer such as a temperature sensor that measures the temperature of the hot water flowing through the hot water supply pipe 23. That is, the hot water temperature measuring unit 43 detects the hot water supply temperature as the temperature of the hot water flowing through the hot water supply pipe 23. The hot water temperature measuring unit 43 includes, for example, a thermoelectric pair as a temperature sensor, and outputs information related to the temperature detected by the thermoelectric pair or the like to the control unit 3 or the water leakage determination device 100. The hot water temperature measuring unit 43 in the present embodiment is provided inside the casing 60 (water heater 1) on the downstream side of the heat exchanger 2 and on the upstream side of the connection portion between the hot water supply pipe 23 and the bypass pipe 22. There is.

As shown in FIG. 2, the water leak determination device 100 includes the tap water temperature measuring unit 7, the water temperature measuring unit 41, the atmosphere temperature measuring unit 42, the hot water temperature measuring unit 43, and the flow rate measuring unit 51 described above. Further, the water leakage determination device 100 includes a communication unit 10, a determination execution unit 11 (an example of a determination unit), a water leakage determination unit 12 (an example of a determination unit), a timekeeping unit 13, a notification unit 14, a storage unit 15, and a learning unit 16. And have. The determination execution unit 11, the water leakage determination unit 12, and the learning unit 16 are configured by software centered on a CPU or memory that executes various processes, or by collaboration between hardware and software. The storage unit 15 is composed of hardware such as RAM and HDD.

The communication unit 10 is an interface for transmitting and receiving to and from the water heater 1 via a wired or wireless network. The communication unit 10 in the present embodiment receives the measured values of the tap water temperature measuring unit 7, the water temperature measuring unit 41, the atmosphere temperature measuring unit 42, the hot water temperature measuring unit 43, and the flow rate measuring unit 51, and also gives an instruction signal to the control unit 3. To send.

The determination execution unit 11 controls the execution of water leakage determination in the hot water supply system X. Upon receiving an instruction signal from the determination execution unit 11 to start the water leakage determination, the water leakage determination unit 12 determines the presence or absence of water leakage. The determination execution unit 11 is predetermined from a standby state in which the measured value of the flow rate measuring unit 51 is less than a predetermined value (for example, 2 liters per minute) or a predetermined value (for example, 2 liters per minute) or more of the measured value of the flow rate measuring unit 51. After stopping the hot water supply that is less than the value, the water leak judgment is executed. Further, the determination execution unit 11 stops the execution of the water leakage determination when the measurement value of the flow rate measurement unit 51 becomes a predetermined value (for example, 2 liters per minute) or more during the water leakage determination. Even if there is a water leak in the hot water supply system X, the amount is usually small, so the measured value of the flow rate measuring unit 51 does not exceed a predetermined value (for example, every 2 liters), and the execution of the water leak determination is stopped. Not done.

It is preferable that the determination execution unit 11 executes the water leakage determination based on the hot water supply period learned by the learning unit 16. For example, during the hot water supply period learned by the learning unit 16, water leakage determination is executed periodically (for example, once a week) during a time period in which there is a high probability that hot water will not be supplied. Further, it is preferable that the determination execution unit 11 changes the execution frequency of the water leakage determination based on the result of the water leakage determination stored in the storage unit 15. For example, when the number of times that there is no water leakage continuously exceeds a predetermined number of times by the water leakage determination, the execution frequency of the water leakage determination is changed from once a week to once every two weeks.

The water leakage determination unit 12 determines the presence or absence of water leakage in the hot water supply system X. When the measured value of the flow rate measuring unit 51 is in a standby state of less than a predetermined value (for example, 2 liters per minute), the start signal of the water leakage determination by the determination executing unit 11 is transmitted to the control unit 3 via the communication unit 10. , The control unit 3 operates the heater H. Then, the water leakage determination unit 12 executes the water leakage determination based on the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42 (first embodiment). As an example, the water leakage determination unit 12 determines that there is no water leakage when the absolute value of the difference between the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42 is equal to or less than a predetermined temperature (for example, 5 ° C.). do. On the contrary, the water leakage determination unit 12 determines that there is a water leakage when the absolute value of the difference between the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42 becomes larger than the predetermined temperature (for example, 5 ° C.). You may. This determination is preferably carried out continuously for a certain period of time (for example, 1 minute).

As another embodiment, after the hot water supply is stopped when the measured value of the flow rate measuring unit 51 becomes less than the predetermined value from a predetermined value (for example, 2 liters per minute) or more, the water leakage determination unit 12 uses the measured value of the tap water temperature measuring unit 7. The water leakage determination is executed based on the measured value of the water temperature measuring unit 41, the measured value of the hot water temperature measuring unit 43, and the measured value of the atmospheric temperature measuring unit 42 (second embodiment). As an example, in the water leakage determination unit 12, the absolute value of the difference between the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42 is equal to or less than a predetermined temperature (for example, 5 ° C.), or the hot water temperature measurement unit 43 If the absolute value of the difference between the measured value of the above and the measured value of the atmosphere temperature measuring unit 42 is equal to or less than a predetermined temperature (for example, 5 ° C.), it is determined that there is no water leakage. Further, when the measured value of the water temperature measuring unit 41 or the hot water temperature measuring unit 43 is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmospheric temperature measuring unit 42, it is determined that there is a water leak. This determination is preferably carried out continuously for a certain period of time (for example, 1 minute).

The timekeeping unit 13 is a timekeeping mechanism that measures the passage of time, starts timekeeping in response to an instruction signal for water leakage determination of the determination execution unit 11, and outputs information related to the elapsed time in response to a request from the water leakage determination unit 12. Output.

The notification unit 14 notifies the result of the water leakage determination by the water leakage determination unit 12. The notification unit 14 is a mechanism that emits a signal to notify the user, the management center, or the like that a water leakage has occurred when the water leakage determination unit 12 determines that there is a water leakage. For example, the notification unit 14 issues a sound, light, or other signal perceptible to the user to notify that a water leak has occurred. In addition, the notification unit 14 can notify a management center or the like that centrally manages the state of the water heater 1 at a remote location via a telecommunication line to notify that a water leak has occurred.

The storage unit 15 stores the hot water supply record by the water heater 1 and the water leak determination record of the water leak determination unit 12. The hot water supply record is composed of the date and time when the hot water supply to the hot water consuming device 90 is executed, the hot water supply flow rate, and the like. The water leak judgment result is composed of the date and time when the water leak judgment was executed, the judgment result, and the like.

The learning unit 16 learns the hot water supply period in which the measured value of the flow rate measuring unit 51 is equal to or more than a predetermined value (for example, 2 liters per minute) based on the hot water supply record by the water heater 1 stored in the storage unit 15. As an example, as shown in FIG. 7, the time is divided by 4 hours for each day of the week, and the hot water supply probability is calculated. If there is an average of about 7 minutes of hot water supply in the past between 0:00 and 4:00 on Monday, the probability of hot water supply will be 3%. The learning of the hot water supply period by the learning unit 16 may be updated each time, or the learning content of a predetermined period (for example, one year) may be fixed.

(Judgment flow of the first embodiment)
The determination method of the water leakage determination device 100 according to the first embodiment will be described with reference to FIGS. 3 to 4.

As shown in FIG. 3, it is determined whether or not the determination executing unit 11 starts the water leakage determination (# 31). The determination of # 31 is performed when the measured value of the flow rate measuring unit 51 is in a standby state of less than a predetermined value (for example, 2 liters per minute). In the present embodiment, the water leakage determination is started in the time zone in which the probability of not supplying hot water is high in the hot water supply period learned by the learning unit 16 (# 31Yes). For example, the determination execution unit 11 uses the table shown in FIG. 7 to determine water leakage between 0:00 and 16:00 on Sunday, which has the lowest probability of not supplying hot water (time zone of 5% or less). To start.

When the control unit 3 receives the start signal of the water leakage determination by the determination execution unit 11, the control unit 3 operates the heater H (# 32). After the control unit 3 operates the heater H, the water leakage determination unit 12 monitors whether or not the hot water supply is started so that the measured value of the flow rate measuring unit 51 becomes a predetermined value (for example, every 2 liters per minute) or more (for example, every 2 liters). # 33). When the measured value of the flow rate measuring unit 51 becomes a predetermined value or more, the water leakage determination unit 12 sends an instruction signal to stop the heater H by the control unit 3 (# 33Yes, # 34). After starting the water leakage determination (after operating the heater H), the timing unit 13 starts timing, and the water leakage determination unit 12 determines whether or not a predetermined time has elapsed (# 33Nо, # 35). ).

As a result of the determination of # 35, if the measured value of the flow rate measuring unit 51 becomes equal to or more than the predetermined value by the time when the predetermined time elapses, the heater H is stopped (# 35Nо, # 33Yes, # 34). On the other hand, as a result of the determination of # 35, when the predetermined time elapses, the water leakage determination unit 12 executes the water leakage determination (# 35Yes, # 36). This predetermined time may be about zero to several seconds, or may be secured for about several minutes in order to improve the determination accuracy.

FIG. 4 shows an example of water temperature behavior measured by the water temperature measuring unit 41 according to the present embodiment. The solid line is the atmospheric temperature inside the casing 60 measured by the atmospheric temperature measuring unit 42, and the two-point chain line is the temperature of tap water in the water pipe W outside the water heater 1 measured by the tap water temperature measuring unit 7. .. Further, the broken line is the temperature of the water in the water supply pipe 21 measured by the water temperature measuring unit 41 when there is no water leakage, and the alternate long and short dash line is the water supply pipe measured by the water temperature measuring unit 41 when there is a water leakage. The temperature of the water in 21.

During hot water supply, tap water from the water pipe W is always supplied to the water supply pipe 21, so that the temperature of the water in the water supply pipe 21 measured by the water temperature measuring unit 41 is as shown by the broken line and the one-point chain line. , The value is close to the temperature of tap water measured by the tap water temperature measuring unit 7. On the other hand, when the hot water supply is stopped, the atmospheric temperature inside the casing 60 gradually decreases as shown by the solid line. At this time, as shown by the broken line, the temperature of the water in the water supply pipe 21 measured by the water temperature measuring unit 41 gradually rises following the ambient temperature when there is no water leakage, but is indicated by a single point chain line. As described above, when there is a water leak, tap water having a low temperature continues to flow through the water supply pipe 21, so that the temperature is maintained at a value close to the temperature of the tap water.

When the heater H is operated, as shown by the solid line, the air inside the casing 60 is heated by heat transfer from the heater H, and the atmospheric temperature inside the casing 60 rises. At this time, as shown by the broken line, the temperature of the water in the water supply pipe 21 measured by the water temperature measuring unit 41 gradually rises following the rise in the atmospheric temperature when there is no water leakage, but the one-point chain line As shown in the above, when there is a water leak, tap water having a low temperature continues to flow through the water supply pipe 21, so that the temperature does not rise or rises slightly.

Therefore, when the control unit 3 operates the heater H and a predetermined time elapses, the water leakage determination unit 12 in the present embodiment leaks water based on the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42. Execute the judgment. Returning to FIG. 3, the water leakage determination unit 12 determines whether or not the absolute value of the difference between the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42 is equal to or less than a predetermined temperature (for example, 5 ° C.). Is determined (# 36).

As a result of the determination of # 36, the water leakage determination unit 12 determines that there is no water leakage if the absolute value of the difference between the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42 is equal to or less than the predetermined temperature. , This determination result is stored in the storage unit 15, and a signal for stopping the heater H is transmitted to the control unit 3 (# 37, # 40). On the other hand, as a result of the determination of # 36, the water leakage determination unit 12 determines that there is a water leak if the absolute value of the difference between the measurement value of the water temperature measurement unit 41 and the measurement value of the atmosphere temperature measurement unit 42 is larger than the predetermined temperature. Then, the notification unit 14 is activated (# 38, # 39). Then, this determination result is stored in the storage unit 15, and a signal for stopping the heater H is transmitted to the control unit 3 (# 40). The determination by the water leakage determination unit 12 may be continuously executed for a certain period of time.

As described above, in the present embodiment, in the standby state while the hot water supply is stopped, the control for raising the temperature of the internal air of the water heater 1 is executed, and the measured value of the water temperature measuring unit 41 and the measured value of the atmospheric temperature measuring unit 42 are executed. The water leak judgment is executed based on. That is, regardless of the frequency of use of the water heater 1, since the inside of the water heater 1 is forcibly heated while the hot water supply is stopped, the temperature of the water supply pipe 21 is raised according to the ambient temperature inside the water heater 1. Is possible. On the other hand, when water leaks in the hot water supply system X, the water temperature of the water supply pipe 21 does not follow the atmospheric temperature inside the water heater 1 because cold water is constantly circulated in the water supply pipe 21. Therefore, even when the inside of the water heater 1 is forcibly heated while the hot water supply is stopped, the water temperature of the water supply pipe 21 does not approach the atmospheric temperature inside the water heater 1, so that the water leakage determination is accurate.

Further, if the water leakage determination is executed based on the hot water supply period learned by the learning unit 16, the water leakage determination can be executed when the water heater 1 is used infrequently. It is possible to prevent the inconvenience that the leakage judgment accuracy is lowered. Further, it is preferable to change the execution frequency of the water leakage determination based on the result of the water leakage determination stored in the storage unit 15. From this, it is possible to reduce energy consumption due to unnecessary water leakage judgment when there is no water leakage, and when there is water leakage, it is possible to increase the reliability of water leakage judgment by increasing the judgment frequency. ..

(Judgment flow of the second embodiment)
The determination method of the water leakage determination device 100 in the second embodiment will be described with reference to FIGS. 5 to 6.

As shown in FIG. 5, the determination execution unit 11 monitors whether or not the water heater 1 has stopped supplying hot water, and determines whether or not to start the water leakage determination (# 51). After the hot water supply is stopped when the measured value of the flow rate measuring unit 51 is from a predetermined value (for example, 2 liters per minute) or more to less than a predetermined value, the water leakage determination is executed (# 51Yes). At this time, among the hot water supply periods learned by the learning unit 16, it is preferable to start the water leakage determination at a time zone in which there is a record of hot water supply but the probability of not supplying hot water is relatively high. For example, the determination execution unit 11 uses the table shown in FIG. 7 to determine water leakage between 8:00 and 12:00 on Friday, which has the highest probability of not supplying hot water (time zone of 5% or less). To start.

The water leakage determination unit 12 monitors whether or not the hot water supply is started when the measured value of the flow rate measuring unit 51 is equal to or higher than a predetermined value (for example, 2 liters per minute) (# 52). When the measured value of the flow rate measuring unit 51 becomes a predetermined value or more, the determination is stopped (# 52Yes, # 53). After the water leak determination is started, the time measuring unit 13 starts the time measurement, and the water leakage determination unit 12 determines whether or not a predetermined time has elapsed (# 54).

As a result of the determination of # 54, if the measured value of the flow rate measuring unit 51 becomes equal to or more than the predetermined value by the time when the predetermined time elapses, the determination is stopped (# 54No, # 52Yes, # 53). On the other hand, as a result of the determination of # 54, when the predetermined time elapses, the water leakage determination unit 12 executes the water leakage determination (# 54Yes, # 55). It is preferable to secure this predetermined time for about several minutes.

FIG. 6 shows an example of hot water temperature behavior measured by the hot water temperature measuring unit 43 according to the present embodiment. The solid line is the atmospheric temperature inside the casing 60 measured by the atmospheric temperature measuring unit 42, and the two-point chain line is the temperature of tap water in the water pipe W outside the water heater 1 measured by the tap water temperature measuring unit 7. .. Further, the broken line is the temperature of the hot water in the hot water supply pipe 23 measured by the hot water temperature measuring unit 43 when there is no water leakage, and the alternate long and short dash line is measured by the hot water temperature measuring unit 43 when there is water leakage. It is the temperature of the hot water in the hot water supply pipe 23.

During hot water supply, the air inside the casing 60 is heated by heat transfer from the heat exchanger 2 as shown by the solid line, and the hot water supply pipe measured by the hot water temperature measuring unit 43 as shown by the broken line and the one-point chain line. Since the temperature of the hot water in the hot water 23 is heated by the heat exchanger 2, it is higher than the ambient temperature inside the casing 60. On the other hand, when the hot water supply is stopped, the atmospheric temperature inside the casing 60 gradually decreases as shown by the solid line. At this time, as shown by the broken line, the temperature of the hot water in the hot water supply pipe 23 measured by the hot water temperature measuring unit 43 gradually decreases so as to approach the atmospheric temperature when there is no water leakage, but it is a one-point chain line. As shown, when there is a water leak, low-temperature tap water continues to flow through the water supply pipe 21, so the temperature drops sharply and converges to a temperature close to the tap water temperature measured by the tap water temperature measuring unit 7. .. Further, as described with reference to FIG. 4 in the first embodiment, when the hot water supply is stopped, the temperature of the water in the water supply pipe 21 measured by the water temperature measuring unit 41 is the ambient temperature when there is no water leakage. However, if there is a water leak, tap water with a low temperature continues to flow through the water supply pipe 21, so that the temperature is maintained at a value close to the temperature of the tap water.

Therefore, the water leakage determination unit 12 in the present embodiment is based on the measured values of the water temperature measuring unit 41 or the hot water temperature measuring unit 43 and the measured values of the atmospheric temperature measuring unit 42 when a predetermined time has elapsed since the hot water supply was stopped. , Execute water leak judgment. Returning to FIG. 5, in the water leakage determination unit 12, the absolute value of the difference between the measured value of the water temperature measuring unit 41 and the measured value of the atmosphere temperature measuring unit 42 is equal to or less than a predetermined temperature (for example, 5 ° C.), or the hot water temperature. It is determined whether or not the absolute value of the difference between the measured value of the measuring unit 43 and the measured value of the atmospheric temperature measuring unit 42 is equal to or less than a predetermined temperature (for example, 5 ° C.) (# 55).

As a result of the determination of # 55, in the water leakage determination unit 12, the absolute value of the difference between the measurement value of the water temperature measurement unit 41 or the hot water temperature measurement unit 43 and the measurement value of the atmosphere temperature measurement unit 42 is equal to or less than a predetermined temperature (for example, 5 ° C.). If (Yes determination), it is determined that there is no water leakage, and the determination result is stored in the storage unit 15 (# 57, # 60). On the other hand, as a result of the determination of # 55, if the absolute value of the difference between the measured value of the water temperature measuring unit 41 or the hot water temperature measuring unit 43 and the measured value of the atmospheric temperature measuring unit 42 is larger than the predetermined temperature ( (Nо determination), it is determined whether or not the measured value of the hot water temperature measuring unit 43 is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmospheric temperature measuring unit 42 (# 56). That is, it is determined whether or not the measured value of the hot water temperature measuring unit 43 has converged to a temperature close to the temperature of tap water. Instead of the measured value of the hot water temperature measuring unit 43, the measured value of the water temperature measuring unit 41 may be used.

As a result of the determination of # 56, in the water leakage determination unit 12, the measured value of the hot water temperature measuring unit 43 (or the water temperature measuring unit 41) is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmospheric temperature measuring unit 42. If it is a value (yes determination), it is determined that there is a water leak, and the notification unit 14 is operated (# 58, # 59). On the other hand, in the water leakage determination unit 12, the measured value of the hot water temperature measuring unit 43 (or the water temperature measuring unit 41) is closer to the measured value of the atmospheric temperature measuring unit 42 than the measured value of the tap water temperature measuring unit 7, that is, the hot water supply. If the temperature of the hot water in the pipe 23 gradually decreases so as to approach the atmospheric temperature (No determination), it is determined that there is no water leakage (# 57). Then, these determination results are stored in the storage unit 15, and the water leakage determination is completed (# 60). The determination by the water leakage determination unit 12 may be continuously executed for a certain period of time. Further, either one of the determinations of # 55 and # 56 may be used.

As described above, in the present embodiment, after the hot water supply is stopped when the measured value of the flow rate measuring unit 51 becomes from a predetermined value or more to less than a predetermined value, the measured value of the water temperature measuring unit 41 or the hot water temperature measuring unit 43 and the atmosphere temperature measuring unit 42 The water leakage judgment is executed based on the measured value of. That is, if the water leakage determination is executed based on the water temperature of the water supply pipe 21 or the hot water temperature of the hot water supply pipe 23 whose temperature change behavior differs depending on the presence or absence of water leakage in the hot water supply system X, the water leakage determination becomes accurate. Further, as in the present embodiment, if the absolute value of the difference between the measured value of the water temperature measuring unit 41 or the hot water temperature measuring unit 43 and the measured value of the atmosphere temperature measuring unit 42 is equal to or less than a predetermined temperature, it is determined that there is no water leakage. Then, the water leakage determination becomes accurate. Further, when the measured value of the hot water temperature measuring unit 43 is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmospheric temperature measuring unit 42, if it is determined that there is a water leak, the water leak determination is made. It will be accurate.

Further, if the water leakage determination is executed based on the hot water supply period learned by the learning unit 16, the water leakage determination can be executed when the water heater 1 is used infrequently. It is possible to prevent the inconvenience that the leakage judgment accuracy is lowered. Further, it is preferable to change the execution frequency of the water leakage determination based on the result of the water leakage determination stored in the storage unit 15. As a result, it is possible to reduce energy consumption due to unnecessary water leakage determination when there is no water leakage, and when there is a water leakage, it is possible to increase the reliability of the water leakage determination by increasing the determination frequency.

[Other Embodiments]
(1) The water leakage determination unit 12 determines the water leakage at the rate of change of the measured value of the water temperature measuring unit 41 in the first embodiment and the second embodiment and the rate of change of the measured value of the hot water temperature measuring unit 43 in the second embodiment. You may judge by. As shown in FIG. 4, when no water leakage has occurred in the hot water supply system X after the hot water supply is stopped, the water temperature of the water supply pipe 21 in the water heater 1 converges to the atmospheric temperature inside the water heater, and the hot water supply system X When water leakage occurs in the water heater 1, the water temperature of the water supply pipe 21 in the water heater 1 hardly changes because cold water is constantly flowing through the water supply pipe 21. Further, as shown in FIG. 6, when water leakage does not occur in the hot water supply system X after the hot water supply is stopped, the hot water temperature of the hot water supply pipe 23 in the hot water supply device 1 converges to the atmospheric temperature inside the hot water supply device 1. When water leaks in the hot water supply system X, cold water flows through the hot water supply pipe 23, so that the hot water temperature of the hot water supply pipe 23 in the water heater 1 converges to the temperature of the tap water outside the hot water supply pipe 1. .. Therefore, if the determination is made based on the measured value of the water temperature measuring unit 41 or the rate of change of the measured value of the hot water temperature measuring unit 43, the water leakage determination becomes accurate.

(2) In the first embodiment, gas may be burned instead of the heater H as a heating source, and the present invention is not particularly limited.
(3) An input unit that receives an execution instruction for water leakage determination to the water leakage determination unit 12 may be provided. This input unit is composed of, for example, a touch panel or a button-type remote controller. Further, the standby state of the water heater 1 that executes the water leakage determination may be a predetermined time after the user inputs the hot water supply stop instruction.
(4) In the first embodiment, the measured value of the hot water temperature measuring unit 43 may be used instead of the measured value of the water temperature measuring unit 41. In the first embodiment and the second embodiment, the measured values of the water temperature measuring unit 41 and the hot water temperature measuring unit 43 may be used instead of the measured values of the water temperature measuring unit 41 or the hot water temperature measuring unit 43. In this case, the determination accuracy of the water leakage determination unit 12 becomes more accurate.
(5) The water leak determination device 100 does not have to include the tap water temperature measuring unit 7.
(6) The determination threshold value in the water leakage determination unit 12 may be changed by learning by the learning unit 16.

The present invention can be used as a water leakage determination device for a hot water supply system having a water heater.

1: Water heater 2: Heat exchanger (heater)
3: Control unit 7: Tap water temperature measurement unit 11: Judgment execution unit (judgment unit)
12: Leakage judgment unit (judgment unit)
14: Notification unit 15: Storage unit 16: Learning unit 21: Water supply pipe 23: Hot water supply pipe 41: Water temperature measurement unit 42: Atmospheric temperature measurement unit 43: Hot water temperature measurement unit 51: Flow rate measurement unit 100: Water leakage determination device W: Water pipe X: Hot water supply system

Claims (11)

A hot water supply pipe provided with a water supply pipe through which water flows, a hot water supply pipe through which hot water flows, a heater that heats water flowing in from the water supply pipe and discharges hot water to the hot water supply pipe, and a control unit that controls operation. It is a water leak judgment device for a hot water supply system that has a container.
A water temperature measuring unit that measures the temperature of the water flowing through the water supply pipe,
Atmosphere temperature measuring unit that measures the temperature of the internal air of the water heater,
A determination unit for executing a water leak determination of the hot water supply system is provided.
The determination unit measures the water temperature when the water heater is in a standby state from when the water heater stops supplying hot water to when the hot water supply starts, and when the control unit executes control to raise the temperature of the internal air of the water heater. A water leak determination device for a hot water supply system that executes the water leak determination based on the measured values of the unit and the measured values of the atmospheric temperature measuring unit. The hot water supply system according to claim 1, wherein the determination unit determines that there is no water leakage when the absolute value of the difference between the measurement value of the water temperature measurement unit and the measurement value of the atmosphere temperature measurement unit is equal to or less than a predetermined temperature. Water leak judgment device. Water leakage of a hot water supply system having a water heater including a water supply pipe through which water flows, a hot water supply pipe through which hot water flows, and a heater for heating water flowing in from the water supply pipe and discharging hot water to the hot water supply pipe. It is a judgment device,
A water temperature measuring unit that measures the temperature of the water flowing through the water supply pipe,
A hot water temperature measuring unit that measures the temperature of hot water flowing through the hot water supply pipe,
Atmosphere temperature measuring unit that measures the temperature of the internal air of the water heater,
A determination unit for executing a water leak determination of the hot water supply system is provided.
The determination unit is the water of the hot water supply system that executes the water leakage determination based on the measured values of the water temperature measuring unit or the hot water temperature measuring unit and the atmospheric temperature measuring unit after the water heater stops supplying hot water. Leakage judgment device. Claim 3 that the determination unit determines that there is no water leakage when the absolute value of the difference between the measurement value of the water temperature measurement unit or the hot water temperature measurement unit and the measurement value of the atmosphere temperature measurement unit is equal to or less than a predetermined temperature. The water leakage determination device of the hot water supply system described in 1. Further provided with a tap water temperature measuring unit for measuring the temperature of water flowing through the water pipe connected to the water supply pipe outside the water heater.
The determination unit determines that there is a water leak when the measurement value of the water temperature measurement unit or the hot water temperature measurement unit is closer to the measurement value of the tap water temperature measurement unit than the measurement value of the atmosphere temperature measurement unit. The water leakage determination device for the hot water supply system according to claim 3 or 4. The water leakage determination device for a hot water supply system according to any one of claims 1 to 5, wherein the determination unit executes the water leakage determination based on the rate of change of the measured value of the water temperature measurement unit. Further equipped with a flow rate measuring unit for measuring the flow rate of water flowing through the water supply pipe,
The water leakage determination device for a hot water supply system according to any one of claims 1 to 6, wherein the determination unit executes the water leakage determination when the measured value of the flow rate measurement unit is less than a predetermined value. Further provided with a learning unit for learning the hot water supply period in which the measured value of the flow rate measuring unit is equal to or greater than the predetermined value.
The water leakage determination device of the hot water supply system according to claim 7, wherein the determination unit executes the water leakage determination based on the hot water supply period learned by the learning unit. The water leakage determination device for a hot water supply system according to claim 7 or 8, wherein the determination unit stops execution of the water leakage determination when the measurement value of the flow rate measurement unit becomes equal to or more than the predetermined value. A storage unit for storing the result of the water leakage determination by the determination unit is further provided.
The water leakage determination device for a hot water supply system according to any one of claims 1 to 9, wherein the determination unit changes the execution frequency of the water leakage determination based on the result. A notification unit for notifying the result of the water leakage determination by the determination unit is further provided.
The water leak determination device for a hot water supply system according to any one of claims 1 to 10, wherein the notification unit is configured to operate when the determination unit determines that there is a water leak.

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