JP2021148392A - Water leakage determination device for hot water supply system - Google Patents

Abstract

To provide a water leakage determination device capable of enhancing water leakage determination accuracy on a hot water storage side in a hot water supply system having the hot water storage.SOLUTION: A water leakage determination device 100 for a hot water supply system X including a hot water storage 1 with water supply piping 51, a storage tank 4, hot water delivery piping 52 and a regulating valve 6 includes: a tap water temperature measurement section 7 measuring a temperature of water flowing in a water pipe W; an atmospheric temperature measurement section 8 measuring a temperature of inside air of the hot water storage 1; a hot water temperature measurement section 9 measuring a temperature of hot water flowing in the hot water delivery piping 52; and a determination section 34 executing a water leakage determination in the hot water supply system X. When the hot water storage 1 is in a waiting state from stop of hot water delivery to start of the hot water delivery and the regulating valve 6 is located in a valve position enabling water in the water supply piping 51 to flow in the hot water delivery piping 52, the determination section 34 executes the water leakage determination on the basis of the measurement value obtained by the tap water temperature measurement section 7, the measurement value obtained by the hot water temperature measurement section 9 and the measurement value obtained by the atmospheric temperature measurement section 8.SELECTED DRAWING: Figure 1

Description

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

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. As one form of this hot water supply system, a hot water storage type hot water supply system having a hot water storage device that stores preheated hot water on the upstream side of the water heater is known, and water is added to the preheated hot water based on the hot water output target temperature. In addition, it is supplied to the water heater from the hot water outlet pipe of the water heater, and if necessary, it is heated by a heat exchanger or the like to supply hot water. 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. Moreover, Patent Document 1 is not a technique for determining water leakage on the water heater side that stores preheated hot water on the upstream side of the water heater.

Therefore, in a hot water supply system having a water storage device, a water leakage determination device capable of improving the water leakage determination accuracy on the water storage device side is desired.

The characteristic configuration of the water leakage determination device of the hot water supply system according to the present invention is a water supply pipe through which water flows, a storage tank that heats the water flowing in from the water supply pipe and stores it as hot water, and the storage tank. It is a water leakage determination device of a hot water supply system having a hot water storage device provided with a hot water discharge pipe for flowing out hot water and a regulating valve for adjusting the amount of water for merging the water of the water supply pipe with the hot water supply pipe, and is outside the hot water storage device. The tap water temperature measuring unit that measures the temperature of the water flowing through the water pipe connected to the water supply pipe, the atmospheric temperature measuring unit that measures the temperature of the internal air of the water storage device, and the downstream side of the regulating valve. The hot water temperature measuring unit for measuring the temperature of the hot water flowing through the hot water outlet pipe located inside the hot water storage device and the determining unit for executing the water leakage determination of the hot water supply system are provided, and the determining unit includes the hot water storage unit. When the adjusting valve is in the valve position where the water in the water supply pipe can be circulated to the hot water outlet pipe in the standby state from the stop of the hot water discharge to the start of the hot water discharge, the measured value of the tap water temperature measuring unit and the hot water temperature. The point is that the water leakage determination is executed based on the measured value of the measuring unit and the measured value of the atmospheric temperature measuring unit.

If there is no water leakage in the hot water supply system in the standby state after the hot water supply is stopped, the hot water temperature of the hot water discharge pipe in the hot water storage device converges to the atmospheric temperature inside the hot water storage device. On the other hand, if a water leak occurs in the hot water supply system in the standby state after the hot water supply is stopped, cold water from the water supply pipe is constantly circulated to the hot water supply pipe via the adjustment valve. The hot water temperature of the pipe does not follow the atmospheric temperature inside the hot water storage, and the hot water temperature of the hot water pipe converges to the temperature of the tap water of the water pipe.

Therefore, in this configuration, when the hot water storage device is in the standby state, the water leakage determination is executed based on the measured value of the tap water temperature measuring unit, the measured value of the hot water temperature measuring unit, and the measured value of the atmospheric temperature measuring unit. That is, if the water leakage determination is executed based on the hot water temperature of the hot water outlet 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.

In this way, since the water leak judgment is executed in the standby state after the hot water supply is stopped, the water leak judgment device of the hot water supply system that can improve the water leak judgment accuracy on the water heater side regardless of the frequency of use of the hot water supply system is provided. I was able to provide it.

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 hot water temperature measurement unit and the measurement value of the atmosphere temperature measurement unit is equal to or less than a predetermined temperature. be.

If there is no water leakage in the hot water supply system in the standby state after the hot water supply is stopped, the hot water temperature of the hot water discharge pipe in the hot water storage device converges to the atmospheric temperature inside the hot water storage device. Therefore, as in this configuration, if it is determined that there is no water leakage when the absolute value of the difference between the measured value of the hot water temperature measuring unit and the measured value of the atmosphere temperature measuring unit is equal to or less than the predetermined temperature, the water leakage determination is made. It will be accurate.

Another characteristic configuration is that the determination unit has a water leak when the measurement value of 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. It is at the point of judging.

If there is a water leak in the hot water supply system in the standby state after the hot water supply is stopped, the cold water from the water supply pipe is constantly flowing to the hot water supply pipe. The temperature of the hot water in the hot water pipe converges to the temperature of tap water without following the internal atmospheric temperature. Therefore, if it is determined that there is a water leak when the measured value of 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 as in this configuration, The water leakage judgment becomes accurate.

Another characteristic configuration further includes a flow rate measuring unit that measures the flow rate of hot water flowing through the hot water outlet pipe, and the determination unit is in the standby state when the measured value of the flow rate measuring unit is less than a predetermined value. The point is to execute the water leakage determination.

In this configuration, it is possible to reliably detect the standby state of the water storage device that executes the water leakage determination.

Another characteristic configuration is that the determination unit is based on the rate of change of the measured value of the hot water temperature measuring unit after the hot water discharge is stopped when the measured value of the flow rate measuring unit becomes less than the predetermined value from the predetermined value or more. The point is to execute the water leak judgment.

Normally, the temperature of tap water is lower than the atmospheric temperature inside the hot water storage and the hot water temperature of the hot water outlet pipe. In other words, if the ambient temperature inside the hot water storage device is higher than the hot water temperature of the hot water outlet pipe after the hot water supply is stopped, the hot water temperature of the hot water outlet pipe will rise when there is no water leak, and the hot water temperature of the hot water outlet pipe will rise when there is a water leak. Since it decreases, the presence or absence of water leakage can be known from the direction of change in the hot water temperature of the hot water outlet pipe. On the other hand, if the ambient temperature inside the hot water storage device is lower than the hot water temperature of the hot water outlet pipe after the hot water discharge is stopped, the hot water temperature of the hot water outlet pipe drops with a gentle gradient when there is no water leak, and when there is a water leak, the hot water discharge pipe Since the hot water temperature drops on a steep slope, the presence or absence of water leakage can be determined from the falling slope of the hot water temperature in the hot water outlet pipe. Therefore, if the water leak determination is executed based on the rate of change of the measured value of the hot water temperature measuring unit after the hot water discharge is stopped as in this configuration, the water leak determination becomes accurate.

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, it is possible to inform the user of the water leak information and promptly take measures to prevent the water leak from the business operator. Is possible.

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 water leakage determination flow chart which concerns on 2nd Embodiment. It is a figure which shows the example of the hot water temperature behavior when the atmospheric temperature is higher than the hot water target temperature. It is a figure which shows the example of the hot water temperature behavior when the atmospheric temperature is lower than the hot water target temperature.

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 and the water heater 10 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 the hot water stored in the water heater 1 by the water heater 10 and supplies it to the hot water consuming device 90 outside the water heater 10. The water leakage determination device 100 in the present embodiment determines the water leakage of the hot water supply system X having the hot water storage device 1. The water leakage determination device 100 is mainly used for water leakage due to damage to the piping system or valve on the downstream side (downstream side of the adjustment valve 6 described later) of the hot water storage device 1 in the hot water supply system X, or for the downstream side due to foreign matter biting into the valve. Determine if there is any water leakage to. The water leakage determination device 100 may be a mechanism that functions as a part of the hot water supply function of the hot water supply system X, or may be a function of a computer provided in a management center that centrally manages the state of the hot water supply system X at a remote location. You may take charge of a part.

The hot water supply system X includes a water heater 10 that supplies hot water to the hot water consuming device 90, a water heater 1 that stores hot water on the upstream side of the water heater 10, and a control unit 2 that controls the operation of the water heater 10 and the water heater 1. It has. The control unit 2 is composed of software centered on a CPU and memory that execute various processes, or collaboration between hardware and software.

The water heater 10 is provided with a pipe 20 inside the casing 60, and the pipe 20 is provided with a heat exchanger 30 which is a hot water supply heat source. The water heater 10 applies the heat obtained from the combustion flame of combustion gas such as natural gas supplied from the gas pipe 31 to the hot water from the water heater 1 circulating in the pipe 20 by the heat exchanger 30 to provide a hot water supply function. It is a gas water heater to run.

The water heater 10 in the present embodiment includes a casing 60, a pipe 20 provided in the casing 60, a heat exchanger 30 provided in the middle of the pipe 20, and a flow rate of hot water supplied from the water heater 1 (hot water supply). It is provided with a flow rate measuring unit 40 for measuring flow rate).

The flow rate measuring unit 40 has a flow meter that measures the flow rate of hot water supplied through the pipe 20 via the heat exchanger 30. The flow rate measuring unit 40 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 2 and the water leakage determination device 100. The lower limit of the dynamic range of the measurement of the flow rate measuring unit 40 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 water heater 1 stores the heat discharged from the heat source 3 as hot water (hot water) (that is, stores heat with hot water as a heat medium), and causes the hot water to flow out to the water heater 10 via the hot water outlet pipe 52. It is configured in. The hot water storage device 1 has a hot water storage tank 4 (an example of a storage tank) for storing hot water (hot water). A water supply pipe 51 to which tap water is supplied is connected to the lower part of the hot water storage tank 4, and the inside of the hot water storage tank 4 is filled with hot water. The heat source 3 can be realized by using various devices that discharge heat, such as a fuel cell, a gas engine cogeneration device, an electric heat pump device, and a solar heat collector.

The hot water storage device 1 in the present embodiment includes a casing 11, a pipe 5 provided in the casing 11 and including a water supply pipe 51 through which water (tap water) from the water pipe W flows and a hot water outlet pipe 52 through which hot water flows. A hot water storage tank 4 provided between the water supply pipe 51 and the hot water supply pipe 52, a heat source 3 for heating the hot water of the hot water storage tank 4, and a regulating valve 6 for adjusting the amount of water for merging the water of the water supply pipe 51 with the hot water supply pipe 52. And have.

The casing 11 is filled with air, and is provided with an atmosphere temperature measuring unit 8 having a thermometer such as a temperature sensor for measuring the temperature of the air. The atmospheric temperature measuring unit 8 includes, for example, a thermocouple or a thermistor (hereinafter referred to as “thermocouple or the like”) as a temperature sensor, and the information related to the temperature detected by the thermocouple or the like is used in the control unit 2 or water leakage determination. Output to device 100.

The pipe 5 is housed inside the casing 11 and is a pipe portion for supplying water and discharging hot water. Of the pipes 5, the pipe 5 on the upstream side of the hot water storage tank 4 is the water supply pipe 51, and the pipe 5 on the downstream side of the hot water storage tank 4 is the hot water outlet pipe 52. Therefore, the pipe 5 stores tap water supplied from the water pipe W outside the casing 11 as hot water in the hot water storage tank 4 as a water supply source, circulates it from the hot water storage tank 4 to the hot water outlet pipe 52, and discharges hot water to the water heater 10. do. The flow rate of the hot water flowing through the hot water discharge pipe 52 is measured by the flow rate measuring unit 40 described above.

The water supply pipe 51 is a piping portion that receives water from the water pipe W outside the hot water storage device 1 and communicates with the hot water storage tank 4, and has a confluence flow path 51a that joins the water to the hot water outlet pipe 52 in parallel with the hot water storage tank 4. doing. The water pipe W is provided with a tap water temperature measuring unit 7. The water supply pipe 51 is provided with a water supply valve 53 and a water temperature measuring unit 54. The water supply pipe 51 in the present embodiment is provided with a water supply valve 53 and a water temperature measuring unit 54 in this order from upstream to downstream, and is a regulating valve in the confluence 51a for merging the water of the water supply pipe 51 with the hot water outlet pipe 52. It is provided on the upstream side of 6. The hot water outlet pipe 52 is a piping unit that communicates with the hot water storage tank 4 and supplies the hot water discharged from the hot water storage tank 4 to the water heater 10. The hot water temperature measuring unit 9 is provided in the hot water outlet pipe 52.

The water supply valve 53 is a valve member composed of a ball valve or the like that controls the flow of water in the water supply pipe 51. As the valve member used for the water supply valve 53, a diaphragm valve, a butterfly valve, or the like can also be used. The water supply valve 53 switches between an open state and a closed state according to an instruction from the control unit 2. That is, water can be supplied to the hot water storage tank 4 with the water supply valve 53 open. Information related to the open / closed state of the water supply valve 53 is output to the control unit 2 and the water leakage determination device 100.

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 54 has a thermometer such as a temperature sensor that measures the temperature of the water flowing through the water supply pipe 51. The tap water temperature measuring unit 7 is provided outside the casing 11 (hot water storage device 1), and the water temperature measuring unit 54 is provided inside the casing 11 (hot water storage device 1). The tap water temperature measuring unit 7 and the water temperature measuring unit 54 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 2 or the water leakage determination device 100.

The hot water temperature measuring unit 9 has a thermometer such as a temperature sensor that measures the temperature of the hot water flowing through the hot water discharge pipe 52. That is, the hot water temperature measuring unit 9 detects the hot water temperature to the water heater 10 as the temperature of the hot water flowing through the hot water pipe 52. The hot water temperature measuring unit 9 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 2 or the water leakage determination device 100. The hot water temperature measuring unit 9 in the present embodiment is on the downstream side of the hot water storage tank 4, and is the casing 11 (hot water storage device 1) on the downstream side of the adjusting valve 6 provided at the connection portion between the hot water outlet pipe 52 and the water supply pipe 51. It is provided inside the.

A hot water circulation path 13 for circulating hot water is connected to the hot water storage tank 4 between the hot water storage tank 4 and the heat source 3. A circulation pump 12 is provided in the middle of the hot water circulation path 13. The hot water circulation path 13 is provided so that hot water taken out from the lower part of the hot water storage tank 4 returns to the upper part of the hot water storage tank 4 via the heat source 3. That is, the relatively low temperature hot water taken out from the lower part of the hot water storage tank 4 recovers the heat in the heat source 3, and the relatively high temperature hot water that recovers the heat discharged from the heat source 3 is the upper part of the hot water storage tank 4. Return to. As a result, in the hot water storage tank 4, relatively high temperature hot water is stored in the upper part, and relatively low temperature hot water is stored in the lower part, so that a temperature stratification is formed and hot water is stored. ..

A hot water discharge pipe 52 for discharging the stored hot water is connected to the upper part of the hot water storage tank 4. The relatively high temperature hot water (hot water) stored in the hot water storage tank 4 is discharged from the hot water outlet pipe 52. In the regulating valve 6, relatively high temperature hot water discharged from the hot water storage tank 4 via the hot water outlet pipe 52 and relatively low temperature water supplied through the water supply pipe 51 flow into the regulating valve 6. The control unit 2 controls the operation of the regulating valve 6 so that the temperature of the hot water flowing from the regulating valve 6 to the hot water outlet pipe 52 on the downstream side becomes the hot water discharge target temperature (for example, 30 to 35 ° C.).

The regulating valve 6 is a valve member composed of a three-way valve or the like that controls the flow rate of hot water in the hot water outlet pipe 52 and the combined flow rate of water from the water supply pipe 51. As the valve member used for the adjusting valve 6, a rotary valve, a solenoid valve, or the like can be used. The adjusting valve 6 adjusts the opening degree of the hot water outlet pipe 52 and the water supply pipe 51 according to the instruction from the control unit 2. That is, the control unit 2 controls the adjusting valve 6 so that the hot water supply pipe 52 is in an open state so that hot water can be discharged to the water heater 10, and controls the communication opening degree of the water supply pipe 51 based on the hot water supply target temperature. On the other hand, when stopping the hot water supply to the water heater 10, the control unit 2 shuts off the hot water discharge pipe 52 on the hot water storage tank 4 side and controls the valve position of the adjusting valve 6 so that the water supply pipe 51 side is fully opened. I will do it. That is, when the hot water supply to the water heater 10 is stopped, the adjusting valve 6 is in a valve position where the water in the water supply pipe 51 can be circulated to the hot water discharge pipe 52. Information related to the valve position of the regulating valve 6 is output to the control unit 2 and the water leakage determination device 100.

As shown in FIG. 2, the water leakage determination device 100 includes the tap water temperature measuring unit 7, the atmosphere temperature measuring unit 8, the hot water temperature measuring unit 9, and the flow rate measuring unit 40 described above. Further, the water leakage determination device 100 includes a communication unit 32, a determination execution unit 33 (an example of a determination unit), a water leakage determination unit 34 (an example of a determination unit), a timekeeping unit 35, a notification unit 36, a storage unit 37, and a learning unit 38. And have. The determination execution unit 33, the water leakage determination unit 34, and the learning unit 38 are configured by software centered on a CPU or memory that executes various processes, or by collaboration between hardware and software. The storage unit 37 is composed of hardware such as a RAM and an HDD.

The communication unit 32 is an interface for transmitting and receiving to and from the hot water storage device 1 via a wired or wireless network. The communication unit 32 in the present embodiment receives the measured values of the tap water temperature measuring unit 7, the atmosphere temperature measuring unit 8, the hot water temperature measuring unit 9, and the flow rate measuring unit 40, and transmits an instruction signal to the control unit 2.

The determination execution unit 33 controls the execution of the water leakage determination in the hot water supply system X. Upon receiving an instruction signal from the determination execution unit 33 to start the water leakage determination, the water leakage determination unit 34 determines the presence or absence of water leakage. The determination execution unit 33 is predetermined from a standby state in which the measured value of the flow rate measuring unit 40 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 40. After the hot water flow rate becomes less than the value (a form of the standby state), the water leakage judgment is executed. Further, the determination execution unit 33 stops the execution of the water leakage determination when the measured value of the flow rate measurement unit 40 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 40 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 33 executes the water leakage determination based on the hot water discharge period learned by the learning unit 38. For example, during the hot water discharge period learned by the learning unit 38, the water leak determination is executed periodically (for example, once a week) during a time zone in which there is a high probability that the hot water will not be discharged. Further, it is preferable that the determination execution unit 33 changes the execution frequency of the water leakage determination based on the result of the water leakage determination stored in the storage unit 37. 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 34 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 40 is less than a predetermined value (for example, 2 liters per minute), the water leakage determination unit 34 is in a standby state, the measured value of the tap water temperature measuring unit 7, the measured value of the hot water temperature measuring unit 9, and the atmosphere. The water leakage determination is executed based on the measured value of the temperature measuring unit 8. As an example, the water leakage determination unit 34 states that there is no water leakage when the absolute value of the difference between the measurement value of the hot water temperature measurement unit 9 and the measurement value of the atmosphere temperature measurement unit 8 is equal to or less than a predetermined temperature (for example, 5 ° C.). Determine (first embodiment). Further, when the measured value of the hot water temperature measuring unit 9 is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmospheric temperature measuring unit 8, it is determined that there is a water leak (first embodiment). .. This determination is preferably carried out continuously for a certain period of time (for example, 1 minute).

After the hot water supply is stopped when the measured value of the flow rate measuring unit 40 becomes less than the predetermined value from a predetermined value (for example, 2 liters per minute) or more, the water leakage determination unit 34 determines the change rate of the measured value of the hot water temperature measuring unit 9. A water leak determination may be performed (second embodiment). As an example, when the measured value of the atmospheric temperature measuring unit 8 is higher than the target temperature of the hot water (measured value of the hot water temperature measuring unit 9) after the hot water is stopped, the hot water temperature of the hot water pipe 14 rises when there is no water leakage. Since the hot water temperature of the hot water outlet pipe 14 drops when there is a water leak, the water leak determination unit 34 determines whether or not there is a water leak based on the direction of change in the hot water temperature of the hot water discharge pipe. On the other hand, when the measured value of the atmospheric temperature measuring unit 8 is lower than the target temperature of the hot water (measured value of the hot water temperature measuring unit 9) after the hot water is stopped, the hot water temperature of the hot water pipe 14 drops due to a gentle gradient when there is no water leakage. However, since the hot water temperature of the hot water outlet pipe 14 drops on a steep slope when there is a water leak, the water leak determination unit 34 determines whether or not there is a water leak based on the falling slope of the measured value of the hot water temperature measuring unit 9. This determination is preferably carried out continuously for a certain period of time (for example, 1 minute).

The timekeeping unit 35 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 33, and outputs information related to the elapsed time in response to a request from the water leakage determination unit 34. Output.

The notification unit 36 notifies the result of the water leakage determination by the water leakage determination unit 34. The notification unit 36 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 34 determines that there is a water leakage. For example, the notification unit 36 emits a sound, light, or other signal that can be perceived by the user to notify that a water leak has occurred. In addition, the notification unit 36 can also communicate to a management center or the like that centrally manages the state of the water heater 10 at a remote location via a telecommunication line to notify that a water leak has occurred.

(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 and 5 to 6.

As shown in FIG. 3, the determination execution unit 33 determines whether or not to start the water leakage determination (whether or not it is in the standby state) (# 31). The determination execution unit 33 executes the water leakage determination when the measured value of the flow rate measurement unit 40 is in the standby state of less than a predetermined value (for example, 2 liters per minute) (# 31Yes). It is preferable to start the water leakage determination during the hot water discharge period learned by the learning unit 16 at a time zone in which the probability of not hot water is relatively high.

The water leakage determination unit 34 monitors whether or not the hot water discharge is started when the measured value of the flow rate measuring unit 40 is equal to or higher than a predetermined value (for example, 2 liters per minute) (# 32). When the measured value of the flow rate measuring unit 40 becomes equal to or more than a predetermined value, the determination is stopped (# 32Yes, # 33). After the water leak determination is started, the time measuring unit 35 starts the time measurement, and the water leakage determination unit 34 determines whether or not a predetermined time has elapsed (# 34).

As a result of the determination of # 34, if the measured value of the flow rate measuring unit 40 becomes equal to or more than the predetermined value by the time when the predetermined time elapses, the determination is stopped (# 34No, # 32Yes, # 33). On the other hand, as a result of the determination of # 34, when the predetermined time elapses, the water leakage determination unit 34 executes the water leakage determination (# 34Yes, # 35). It is preferable to secure this predetermined time for about several minutes.

FIG. 5 shows an example of hot water temperature behavior measured by the hot water temperature measuring unit 9 when the measured value of the atmospheric temperature measuring unit 8 is higher than the hot water target temperature as in summer. An example of hot water temperature behavior measured by the hot water temperature measuring unit 9 when the measured value of the atmospheric temperature measuring unit 8 is lower than the hot water target temperature as in winter is shown. The broken line is the atmospheric temperature inside the casing 60 measured by the atmospheric temperature measuring unit 8, the one-dot chain line is the hot water target temperature, and the two-dot chain line is the inside of the water pipe W measured by the tap water temperature measuring unit 7. The temperature of tap water. The solid lines in FIGS. 5 (a) and 6 (a) are the temperatures of the hot water in the hot water outlet pipe 52 measured by the hot water temperature measuring unit 9 when there is no water leakage, and are shown in FIGS. 5 (b) and 6 (a). The solid line of 6 (b) is the temperature of the hot water in the hot water outlet pipe 52 measured by the hot water temperature measuring unit 9 when there is a water leak.

During hot water discharge, as shown by the solid lines in FIGS. 5 and 6, the opening degree of the adjusting valve 6 is adjusted so that the temperature of the hot water in the hot water discharge pipe 52 measured by the hot water temperature measuring unit 9 becomes the hot water discharge target temperature. Has been done. On the other hand, when the hot water is stopped, the temperature of the hot water in the hot water pipe 52 measured by the hot water temperature measuring unit 9 is when there is no water leakage as shown by the solid lines in FIGS. 5 (a) and 6 (a). As shown by the solid lines in FIGS. 5 (b) and 6 (b), when there is a water leak, tap water with a low temperature continues to flow through the water supply pipe 51. , It drops sharply and converges to a temperature close to the temperature of tap water measured by the tap water temperature measuring unit 7.

Therefore, when a predetermined time elapses after the hot water supply is stopped, the water leakage determination unit 34 in the present embodiment measures the tap water temperature measurement unit 7, the hot water temperature measurement unit 9, and the atmosphere temperature measurement unit 8. Based on the above, the water leakage determination is executed. Returning to FIG. 3, the water leakage determination unit 34 determines whether or not the absolute value of the difference between the measured value of the hot water temperature measuring unit 9 and the measured value of the atmospheric temperature measuring unit 8 is equal to or less than a predetermined temperature (for example, 5 ° C.). Is determined (# 35).

As a result of the determination of # 35, if the absolute value of the difference between the measured value of the hot water temperature measuring unit 9 and the measured value of the atmospheric temperature measuring unit 8 is equal to or less than the predetermined temperature (for example, 5 ° C.), the water leakage determining unit 34 is water. It is determined that there is no omission, and the determination result is stored in the storage unit 37 (# 37, # 40). On the other hand, as a result of the determination of # 35, if the absolute value of the difference between the measured value of the hot water temperature measuring unit 9 and the measured value of the atmospheric temperature measuring unit 8 is larger than the predetermined temperature, the water leakage determining unit 34 is the hot water temperature measuring unit 9. It is determined whether or not the measured value of is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmosphere temperature measuring unit 8 (# 36). That is, it is determined whether or not the measured value of the hot water temperature measuring unit 9 has converged to a temperature close to the temperature of tap water. Instead of the measured value of the tap water temperature measuring unit 7, the measured value of the water temperature measuring unit 54 may be used. This is because the temperature of the air in the hot water storage device 1 hardly fluctuates depending on the presence or absence of hot water, and the temperature of the water in the water supply pipe 51 is close to the temperature of tap water.

As a result of the determination of # 36, if the measured value of the hot water temperature measuring unit 9 is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmospheric temperature measuring unit 8, the water leakage determining unit 34 leaks water. Is determined to be present, and the notification unit 36 is activated (# 38, # 39). On the other hand, in the water leakage determination unit 34, the measured value of the hot water temperature measuring unit 9 is closer to the measured value of the atmospheric temperature measuring unit 8 than the measured value of the tap water temperature measuring unit 7, that is, the temperature of the hot water in the hot water outlet pipe 14. If is gradually changing so as to approach the ambient temperature, it is determined that there is no water leakage (# 37). Then, these determination results are stored in the storage unit 37, and the water leakage determination is completed (# 40). The determination by the water leakage determination unit 34 may be continuously executed for a certain period of time. Moreover, either one of the determinations of # 35 and # 36 may be used.

As described above, in the present embodiment, the water leakage determination is executed based on the measured value of the tap water temperature measuring unit 7, the measured value of the hot water temperature measuring unit 9, and the measured value of the atmosphere temperature measuring unit 8 while waiting for the hot water to flow out. .. That is, if the water leakage determination is executed based on the hot water temperature of the hot water outlet pipe 14 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 it is determined that there is no water leakage when the absolute value of the difference between the measured value of the hot water temperature measuring unit 9 and the measured value of the atmosphere temperature measuring unit 8 is equal to or less than the predetermined temperature, water leakage occurs. The judgment will be accurate. Further, when the measured value of the hot water temperature measuring unit 9 is closer to the measured value of the tap water temperature measuring unit 7 than the measured value of the atmospheric temperature measuring unit 8, if it is determined that there is a water leak, the water leak determination is made. It will be accurate.

Further, if the water leak determination is executed based on the hot water discharge period learned by the learning unit 38, the water leak determination can be executed when the water storage device 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 37. 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.

(Judgment flow of the second embodiment)
A method for determining the water leakage determination device 100 according to the second embodiment will be described with reference to FIGS. 4 to 6. Since this embodiment may be executed at the same time as or in parallel with the first embodiment, only a configuration different from that of the first embodiment will be described.

As shown in FIG. 4, the determination execution unit 33 monitors whether or not the hot water storage device 1 has stopped the hot water supply, and determines whether or not to start the water leakage determination (# 41). After the hot water discharge is stopped when the measured value of the flow rate measuring unit 40 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 (# 41Yes). At this time, it is preferable to start the water leakage determination at a time zone in which the probability of not hot water is relatively high in the hot water discharge period learned by the learning unit 16.

As shown by the solid lines in FIGS. 5A and 5B, when the measured value of the atmospheric temperature measuring unit 8 is higher than the hot water target temperature, the measured value of the flow rate measuring unit 40 changes in the direction of change depending on the presence or absence of water leakage. Differently, as shown by the solid lines in FIGS. 6A and 6B, when the measured value of the atmospheric temperature measuring unit 8 is lower than the hot water target temperature, the measured value of the flow rate measuring unit 40 changes depending on the presence or absence of water leakage. The direction is the same, but the change gradient is different.

Therefore, the water leakage determination unit 34 in the present embodiment leaks water based on the rate of change of the measured value of the hot water temperature measuring unit 9 after the hot water discharge is stopped when the measured value of the flow rate measuring unit 40 becomes less than the predetermined value. Execute the judgment. Returning to FIG. 4, the water leakage determination unit 34 acquires the rate of change of the measured value of the hot water temperature measuring unit 9 (change gradient of the hot water temperature), and the measured value of the atmospheric temperature measuring unit 8 is larger than the hot water target temperature. It is determined whether it is high or not (# 42, # 43).

When the measured value of the atmospheric temperature measuring unit 8 is higher than the hot water target temperature (# 43Yes), the water leakage determination unit 34 determines whether or not the measured value of the hot water temperature measuring unit 9 has an ascending gradient (# 44). The water leakage determination unit 34 determines that there is no water leakage if the measurement value of the hot water temperature measurement unit 9 is an ascending gradient as a result of the determination of # 44 (Yes determination), and stores this determination result in the storage unit 37. (# 46, # 49). On the other hand, the water leakage determination unit 34 determines that there is a water leak if the measurement value of the hot water temperature measurement unit 9 is a downward slope (Nо determination) as a result of the determination of # 44, and activates the notification unit 36. The determination result is stored in the storage unit 37 (# 47, # 48, # 49).

When the measured value of the atmospheric temperature measuring unit 8 is lower than the hot water target temperature (# 43Nо), the water leakage determination unit 34 determines whether or not the descending gradient of the measured value of the hot water temperature measuring unit 9 is steeper than the predetermined gradient. (# 45). As a result of the determination of # 45, the water leakage determination unit 34 determines that there is a water leak if the downward slope of the measured value of the hot water temperature measurement unit 9 is steep (Yes determination), and activates the notification unit 36. This determination result is stored in the storage unit 37 (# 47, # 48, # 49). On the other hand, the water leakage determination unit 34 determines that there is no water leakage if the downward gradient of the measured value of the hot water temperature measurement unit 9 is gentle (Nо determination) as a result of the determination of # 44, and stores this determination result. It is stored in the part 37 (# 46, # 49). The determination by the water leakage determination unit 34 may be continuously executed for a certain period of time.

As described above, in the present embodiment, when the hot water discharge, which is the initial stage of the hot water discharge standby, is stopped, if the water leak determination is executed based on the rate of change of the measured value of the hot water temperature measuring unit 9, the water leak determination is accurate. It becomes a thing.

[Other Embodiments]
(1) An input unit that receives an execution instruction for water leakage determination to the water leakage determination unit 34 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 hot water storage device 1 that executes the water leakage determination may be a predetermined time after the user inputs the hot water supply stop instruction.
(2) The water leak determination device 100 does not have to include the water temperature measuring unit 54. In the second embodiment, since the measured value of the hot water temperature measuring unit 9 approaches the hot water discharge target temperature during hot water discharge, the measured value of the hot water temperature measuring unit 9 may be used instead of the hot water discharge target temperature in # 43 of FIG. good.
(3) Although the flow rate measuring unit 40 is provided inside the water heater 10, it may be provided in the hot water outlet pipe 14 on the downstream side of the adjusting valve 6 inside the water heater 1.
(4) The determination threshold value in the water leakage determination unit 34 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 hot water storage device.

1: Hot water storage device 4: Hot water storage tank (storage tank)
6: Adjusting valve 7: Tap water temperature measurement unit 8: Atmosphere temperature measurement unit 9: Hot water temperature measurement unit 14: Hot water outlet piping 33: Leakage determination unit (judgment unit)
34: Judgment execution unit (judgment unit)
36: Notification unit 40: Flow rate measurement unit 51: Water supply pipe 52: Hot water supply pipe 100: Judgment device W: Water pipe X: Hot water supply system

Claims (6)

A water supply pipe through which water flows, a storage tank that heats the water flowing in from the water supply pipe and stores it as hot water, a hot water outlet pipe that discharges the hot water stored in the storage tank, and the water supply pipe to the hot water supply pipe. A water leak determination device for a hot water supply system having a water storage device equipped with a regulating valve for adjusting the amount of water to be merged.
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 storage device, and a tap water temperature measuring unit.
An atmosphere temperature measuring unit that measures the temperature of the internal air of the water storage device,
A hot water temperature measuring unit that measures the temperature of hot water flowing through the hot water outlet pipe located inside the hot water storage device on the downstream side of the regulating valve.
A determination unit for executing a water leak determination of the hot water supply system is provided.
The determination unit is a tap water temperature measuring unit when the adjusting valve is in a valve position where water in the water supply pipe can be circulated to the hot water supply pipe in a standby state from when the hot water storage device stops hot water to when hot water is started. A water leak determination device for a hot water supply system that executes the water leak determination based on the measured value of the water temperature measuring unit, the measured value of the hot water temperature measuring unit, and the measured value 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 hot 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. Claim 1 that the determination unit determines that there is a water leak when the measurement value of 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. Or the water leakage determination device of the hot water supply system according to 2. It is further equipped with a flow rate measuring unit that measures the flow rate of hot water flowing through the hot water outlet pipe.
The hot water supply system according to any one of claims 1 to 3, wherein the determination unit is in the standby state when the measurement value of the flow rate measurement unit is less than a predetermined value, and executes the water leakage determination. Water leak judgment device. The determination unit executes the water leakage determination based on the rate of change of the measured value of the hot water temperature measuring unit after the hot water discharge is stopped when the measured value of the flow rate measuring unit becomes less than the predetermined value from the predetermined value or more. The water leakage determination device for the hot water supply system according to claim 4. 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 5, wherein the notification unit is configured to operate when the determination unit determines that there is a water leak.

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