JPH0650608A - Dry burning preventing method for hot water storage type hot water feeder - Google Patents

Abstract

PURPOSE:To prevent the occurrence of dry-burning by a method wherein a flow rate of water fed to a hot water storage tank during restoration of outage is measured. CONSTITUTION:By performing drainage of a part of water in a hot water storage tank at a temporary drain process 13 during restoration of outage, a state where water can be fed at a next water feeding process 14 is produced regardless of whether the hot water storage tank is full of water, and with this state, water is fed. It is decided at a flow rate measuring process 15 and a flow rate deciding process 16 whether water can be fed. When it is decided that water can not be fed, heating by a heating device is prohibited at a heating prohibiting process 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing emptying of a hot water storage type hot water supply apparatus which can prevent an emptying by detecting an abnormality in a water supply system when a power failure is restored.

[0002]

2. Description of the Related Art In recent years, in a house such as a resort condominium that is not used continuously, from the viewpoint of safety, central control of the water heater of each house or remote control (telecontrol) using a telephone line is possible. I started to do it. The period of using the water heater in a place such as a resort condominium is often a limited period such as a weekend. Therefore, when the hot water storage type water heater is not used, the water in the hot water storage tank is drained to prevent the deterioration of water quality. Therefore,
When a water heater is used, water is supplied to the water heater and an operation command for the heating device is issued by remote control from a manager's room or the like.

Conventionally, this kind of hot water storage type water heater is disclosed in Japanese Patent Laid-Open No.
Prevention of emptying is performed by a method as disclosed in Japanese Patent Laid-Open No. 305253. Hereinafter, the method will be described with reference to FIG.

FIG. 4 is an operational flowchart of a conventional method for preventing emptying of a hot water storage type hot water supply apparatus, showing an example in which the capacity of the hot water storage tank is 300 liters and the heating device is an electric heater. Water supply processing 50 is performed in the water supply mode to the hot water storage type water heater, and drainage processing 51 is performed in the drainage mode. In the water supply process 50, first, the drain valve is closed (step 52), then the water supply valve is opened (step 53), and water supply is started. The water supply flow rate is measured by a flow rate sensor (not shown), and it is determined whether the integrated flow rate is 100 liters or more (step 54). If it is 100 liters or more, it is determined that there is no abnormality in the water supply system and the water can be supplied. To do. If the accumulated flow rate is 100 liters or more, it is determined whether it is 300 liters or less (step 55),
If the water supply stops at 300 liters or less, it is determined that the water does not continue to flow due to opening of the hot water supply valve or failure of the safety valve. That is, the flow rate of water supplied to the hot water storage tank is detected by the flow rate sensor, and if the flow rate of water supply is stopped when the flow rate of water supplied becomes substantially equal to the capacity of the hot water storage tank, it is assumed that the hot water storage tank is full and the heater energization has started.

[0005]

In such a conventional hot water storage type water heater, since the water supply flow rate measured by the flow rate sensor is stored in an electric circuit such as a microcomputer, after the hot water storage tank is full of water. If there is a power outage, the water supply flow rate will be lost. Therefore, when the water supply flow rate is almost equal to the capacity of the hot water storage tank even after the power failure is restored, if the condition of full water is to stop the water supply flow rate, the hot water storage tank is originally full. Since it is, the water supply flow rate is 0 and it is judged that it is not full,
There is a problem in that it is extremely inconvenient because it stops abnormally without heating by the heating device and also abnormally stops each time a power failure occurs.

[0006] Further, in order to prevent an abnormal stop at each power failure, at the time of power failure recovery, the water supply flow rate is 100 liters or more 30
If it is judged to be full when the hot water supply flow rate reaches 0 without making a determination of 0 liters or less, heating is performed by the heating device, which is convenient, but in this case, the water supply flow rate is 0.
There are two cases, that is, the hot water storage tank is full and water cannot be supplied any more, and there is an abnormality in the water supply system such as the main tap of the water supply pipe being closed and water cannot be supplied. If the hot water storage tank is empty and water cannot be supplied due to an abnormality in the water supply system when the power is restored, the water supply flow rate will be 0, so it is determined that the hot water storage tank is full, and heating is started by the heating device and then empty. It had the problem of being lost. Especially at the time of trial operation, the power was often turned off or the water supply was stopped due to the construction work, and there was a high risk of the above problems occurring.

SUMMARY OF THE INVENTION The first object of the present invention is to solve the above problems and to reliably detect an abnormality in the water supply system at the time of restoration from a power failure to prevent emptying and improve usability.

A second object is to detect an abnormality in the water supply system at the time of restoration from a power failure, prevent emptying, shorten the time until the abnormality in the water supply system is detected, and further improve usability.

[0009]

In order to achieve the first object of the present invention, the operation mode before a power failure at the time of recovery from a power failure is either a water supply mode to a hot water tank or a drainage mode from the hot water tank. And a mode determination step of determining whether
In the water supply step, a temporary drainage step of performing drainage from the hot water storage tank for a predetermined time when the mode determination step determines that the water supply mode is provided, and a water supply step of supplying water to the hot water storage tank after the temporary drainage step. A flow rate measuring step of measuring the water supply flow rate to the hot water storage tank, a flow rate determining step of determining whether the flow rate measured in the flow rate measuring step has reached a predetermined flow rate within a predetermined time, and a predetermined flow rate in the flow rate determining step. The first problem solving means is to include a heating prohibition step of stopping the heating device if the water supply is abnormal if the water supply is less than the predetermined value.

In order to achieve the above second object,
When it is determined that the operation mode before the power failure is a water supply mode to the hot water storage tank or a drainage mode from the hot water storage tank when returning from the power failure, and the mode determination step is the water supply mode In the water supply and drainage step of performing drainage for a predetermined time while supplying water to the hot water storage tank, a flow rate measurement step of measuring the water supply flow rate to the hot water storage tank in the water supply and drainage step, and the flow rate measured in the flow rate measurement step is a predetermined flow rate. The second problem solving means is provided with a flow rate determination step of determining whether the flow rate has reached the limit and a heating prohibition step of stopping the heating device as a water supply abnormality if the flow rate is less than a predetermined flow rate in the flow rate determination step.

[0011]

According to the first means for solving the above problems, the present invention provides:
If it is in the water supply mode when returning from a power outage, the water in the hot water storage tank can be partially drained in the temporary drainage process, regardless of whether the hot water storage tank is full or not. By supplying water in this state, it is judged in the flow rate measurement process and flow rate judgment process whether or not water can be supplied, and if it is judged that water supply is not possible, by prohibiting heating by the heating device in the heating prohibition process , It is possible to prevent emptying when power is restored.

Further, according to the second means for solving the problem, if the water supply mode is used at the time of recovery from the power failure, is the water in the hot water storage tank filled with water by supplying water in the hot water storage tank in the water supply / drainage process? Whether or not water can be supplied can be created, and whether or not water can be supplied in this state is determined in the flow rate measurement process and flow rate determination process.If it is determined that water cannot be supplied, heating by the heating device is performed in the heating prohibition process. By prohibiting it, it is possible to prevent emptying when power is restored and drain water while supplying water in the water supply and drainage process, so the time required for drainage can be omitted and the time until it determines an abnormality in the water supply system in the flow rate determination process is shortened. it can.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for preventing emptying of a hot water storage type water heater according to a first embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 is a system configuration diagram of the first embodiment of the present invention. A water supply pipe from a water supply source is connected to a hot water storage tank 4 via a pressure reducing valve 1, a water supply electric valve 2 and a flow rate sensor 3. is doing. The flow rate sensor 3 measures the water supply flow rate. The water introduced to the hot water storage tank 4 is heated by the heating device 5. A hot water supply pipe 6 is connected to the upper part of the hot water storage tank 4, and the water heated by the heating device 5 is introduced. The hot water supply pipe 6 is provided with a hot water relief valve 7 and an air vent valve 8 with a negative pressure differential valve. The hot water supply relief valve 7 releases the expanded water at the time of heating by the heating device 5, and the air vent valve 8 with a negative pressure differential valve releases the air in the hot water storage tank 4 when supplying water to the hot water storage tank 4. A drainage pipe 9 is connected to the lower portion of the hot water storage tank 4, and a drainage electric valve 10 is provided in the drainage pipe 9. The control device 11 controls the operations of the electric water supply valve 2, the heating device 5, and the electric drainage valve 10, and the operation mode before the power failure at the time of recovery from the power failure is the water supply mode to the hot water tank 4 or the hot water tank 4. To the hot water storage tank 4 after the temporary water discharge step, a mode determination step for determining which of the drainage modes was performed, a temporary drainage step for draining the hot water storage tank 4 for a predetermined time when the mode determination step was determined to be the water supply mode Water supply process for supplying water, a flow rate measurement process for measuring the flow rate of water supplied to the hot water storage tank 4 in the water supply process, and a flow rate determination for determining whether the flow rate measured in the flow rate measurement process has reached a predetermined flow rate within a predetermined time If the flow rate is less than a predetermined flow rate in the flow rate determination step, each step of the heating prohibition step that stops the heating device 5 as a water supply abnormality is controlled.

In the above structure, a method for preventing emptying at the time of restoration from a power failure will be described with reference to FIG.
Upon recovery from a power failure, the mode determination process 12 determines whether the mode before the power failure is the water supply mode or the drainage mode (step 18).
I do. If the drainage mode is determined in the mode determination step 12, the process proceeds to drainage mode processing (step 28) to drain the water in the hot water storage tank 4. Mode determination process 12
If it is determined that the water supply mode is set, the process proceeds to the temporary drainage process 13. In the temporary drainage process 13, first drainage is started (step 19), and drainage is stopped after a predetermined time has passed (step 20).
To do. The drainage is performed by opening the drainage motor-operated valve 10. If the temporary drainage process 13 is executed, the hot water storage tank 4
Even when the inside of the hot water storage tank 4 is already full, a part of the water in the hot water storage tank 4 is drained, so that further water can be supplied.

After the temporary drainage process 13, the process proceeds to the water supply process 14 to start water supply (step 21). Water supply is performed by opening the water supply motor operated valve 2. After the start of water supply, the flow proceeds to the flow rate measuring step 15, and the flow rate is measured by the flow rate sensor 3 (step 22). In the flow rate determination step 16, it is determined whether the flow rate measured in the flow rate measurement step 15 has reached the predetermined flow rate S1 (step 23). If the flow rate is greater than or equal to the predetermined flow rate S1 in step 23, the process proceeds to step 27 and water supply mode processing is performed. In the water supply mode process, the water supply is further continued, and if the flow rate sensor 3 can no longer detect the flow rate, it is determined that the water is full, and heating is performed by the heating device 5. Step 23
If the flow rate is less than the predetermined flow rate S1, the process proceeds to step 24 and it is determined whether a predetermined time has elapsed. If the predetermined time has not elapsed, the flow returns to step 22 to continue the flow rate measurement, and if the predetermined time has elapsed, the process proceeds to the heating prohibition step 17. If the flow rate determination step 16 does not reach the predetermined flow rate S1 within the predetermined time, it is determined that water cannot be supplied due to an abnormality in the water supply system, and heating by the heating device 5 is prohibited in the heating prohibition step 17 (step 25). Prevent the heater 5 from emptying. Since the abnormality of the water supply system is confirmed in step 25, the water supply is stopped in step 26.

As described above, according to this embodiment, if the water supply mode is used at the time of recovery from a power failure, the temporary drainage process 13
By partially draining the water in the hot water storage tank 4, the next water supply step 1 regardless of whether the hot water storage tank 4 is full or not.
In step 4, water is supplied, water is supplied in this state, and whether or not water can be supplied is determined in the flow rate measurement step 15 and the flow rate determination step 16. If it is determined that water cannot be supplied, the heating device 5 is used in the heating inhibition step 17. Since the heating is prohibited, even if a sensor such as a water level sensor or a water detection electrode other than the flow rate sensor 3 is not used, the emptying can be prevented when the power is restored.

The storage of the operation mode before the power failure can be realized by using a latching relay, an EEPROM (electrically writable / electrically erasable ROM) or the like. The flow rate measured in the flow rate measurement step 15 and the flow rate determined in the flow rate determination step 16 are the flow rate per unit time (liter / minute).
However, the integrated flow rate (liter) is also acceptable. That is,
It suffices if it can be confirmed that water is supplied after being partially drained from the hot water storage tank 4 in the drainage step 13.

Next, a second embodiment of the present invention will be described. The control device 11 in FIG. 2 has a mode determination step and a mode determination step that determine whether the operation mode before the power failure is the water supply mode to the hot water tank 4 or the drainage mode from the hot water tank 4 at the time of recovery from the power failure. When it is determined to be in the water supply mode, water is supplied to the hot water storage tank 4 while draining water for a predetermined time, a flow rate measurement step of measuring the water supply flow rate to the hot water storage tank 4 in the water supply and drainage step, and a flow rate measurement step Each of the flow rate determination step of determining whether or not the determined flow rate has reached a predetermined flow rate and the heating inhibition step of stopping the heating device 5 as a water supply abnormality if the flow rate determination step is less than the predetermined flow rate are controlled. The other structure is the same as that of the first embodiment.

In the above structure, a method for preventing emptying when power is restored will be described with reference to FIG.
When the power is restored from the power failure, the mode determination step 29 determines whether the mode before the power failure is the water supply mode or the drainage mode (step 34).
I do. When it is determined in the mode determination step 29 that the drainage mode is set, the process proceeds to the drainage mode process (step 43) to drain the water in the hot water storage tank 4. Mode determination process 29
When it is determined that the water supply mode is selected in step S30, the process proceeds to the water supply / drainage process 30. In the water supply / drainage process 30, water supply is started (step 35) and drainage is started (step 36). Water supply is performed by opening the water supply motor-operated valve 2, and drainage is performed by opening the drainage motor-operated valve 10. Water supply and drainage process 30
If the above is executed, even if the hot water storage tank 4 is already full before the power failure, the water can be further supplied by the amount drained from the hot water storage tank 4.

After the water supply / drainage step 30, the flow proceeds to the flow rate measuring step 31, and the flow rate is measured by the flow rate sensor 3 (step 37).
To do. Then, after a lapse of a predetermined time from the water supply / drainage process 30, the drainage is stopped in step 38. In the flow rate determination step 32,
It is determined whether the flow rate measured in the flow rate measuring step 31 has reached a predetermined flow rate S1 (step 39). Flow rate determination process 3
If the flow rate is greater than or equal to the predetermined flow rate S1 in step 2, the process proceeds to step 42 and water supply mode processing is performed. In the water supply mode process, if the flow sensor 3 continues to supply water and the flow rate sensor 3 no longer detects the flow rate, it is determined that the water is full and heating is performed by the heating device 5. If the flow rate is less than the predetermined flow rate S1 in the flow rate determination step 32, it is determined that water cannot be supplied due to an abnormality in the water supply system, and heating in the heating inhibition step 33 is prohibited (step 40). Prevent emptying. Step 4
Since an abnormality in the water supply system has been confirmed at 0, step 41
Then stop water supply.

As described above, according to the present embodiment, if the water supply mode is used at the time of recovery from a power failure, the water in the hot water storage tank 4 is being drained while water is being supplied in the water supply / drainage step 30, so It is possible to create a state where water can be supplied regardless of whether or not it is full, and whether or not water can be supplied in this state is determined in the flow rate measurement step 31 and the flow rate determination step 32, and if it is determined that water cannot be supplied, heating is prohibited. Since the heating by the heating device 5 is prohibited in the step 33, it is possible to prevent emptying at the time of restoration from the power failure without using a sensor such as the water level sensor or the water detection electrode other than the flow rate sensor 3. Further, since the water is drained while being supplied in the water supply / drainage step 30, the time required for draining can be omitted as compared with the first embodiment, and the time until the flow rate determination step 32 determines the abnormality of the water supply system is shortened. be able to.

Further, since the water is supplied while being drained in the water supply / drainage step 30, the temperature of the drainage does not rise, so that the drainage pipe 9 is not damaged and dew condensation due to water vapor does not occur. In other words, even if the inside of the hot water storage tank 4 is full of water before the power failure and the heating by the heating device 5 is completed, and the water in the hot water storage tank 4 is at a high temperature, the water supply pipe and the drain pipe 9 are located below the hot water storage tank 4. Since it is installed in the water, the supplied water will be drained as it is, and the temperature of the drainage will not rise.

The storage of the operation mode before the power failure can be realized by using a latching relay, an EEPROM (electrically writable / electrically erasable ROM) or the like. The flow rate measured in the flow rate measurement step 31 and the flow rate determined in the flow rate determination step 32 are the flow rate per unit time (liter / minute).
However, the integrated flow rate (liter) is also acceptable. That is,
It suffices if it can be confirmed that water is supplied after being discharged from the hot water storage tank 4 in the water supply / drainage process 30. Further, in the water supply / drainage process 30, water supply start (step 35) and drainage start (step 3)
Either of 6) may be performed first.

The predetermined flow rate S1 in each of the above embodiments
When the flow rate per unit time is, the predetermined flow rate S1 is
The value is set to a value smaller than the normal water supply flow rate (10 liters / minute), for example, a value such as 5 liters / minute. Further, when the predetermined flow rate S1 in each embodiment is set as the integrated flow rate, the predetermined flow rate S1 is the temporary drainage process 13 or the water supply / drainage process 30.
It is set to a value smaller than the amount of water drained in (for example, 10 liters), such as 5 liters. Also,
Although an example of flow rate measurement by the flow rate sensor 3 is shown in FIG. 2, it goes without saying that the same effect can be obtained by using a sensor that operates a switch when a flow rate higher than a predetermined flow rate is detected, such as a flow switch. Nor.

[0026]

As is apparent from the above embodiments, according to the present invention, if the water supply mode is used at the time of recovery from a power failure, the hot water storage is performed by partially draining the water in the hot water storage tank in the temporary drainage process. Regardless of whether or not the tank is full, it creates a state where water can be supplied in the next water supply process, water is supplied in this state, and whether or not water can be supplied is determined in the flow rate measurement process and flow rate determination process, and water cannot be supplied. If it is determined that heating is prohibited by the heating device in the heating prohibition step, it is possible to reliably detect an abnormality in the water supply system when power is restored and prevent emptying, and improve usability.

Further, if the water supply mode is set at the time of recovery from a power failure, the water in the hot water storage tank can be supplied regardless of whether or not the hot water storage tank is full by draining the water in the hot water storage tank in the water supply / drainage process. A state is created, and whether water can be supplied in this state is determined in the flow rate measurement process and flow rate determination process.If it is determined that water cannot be supplied, heating by the heating device is prohibited in the heating prohibition process. It is possible to reliably prevent emptying by detecting an abnormality in the system, shorten the time until detecting an abnormality in the water supply system, and further improve usability.

[Brief description of drawings]

FIG. 1 is an operation flowchart of an emptying prevention method for a hot water storage water heater according to a first embodiment of the present invention.

FIG. 2 is a system configuration diagram of a hot water storage type water heater provided with the emptying prevention method.

FIG. 3 is an operation flowchart of a method for preventing emptying of the hot water storage type water heater according to the second embodiment of the present invention.

FIG. 4 is an operation flowchart of a conventional method for preventing emptying of a hot water storage type water heater.

[Explanation of symbols]

 4 Hot Water Storage Tank 12 Mode Determination Process 13 Temporary Drainage Process 14 Water Supply Process 15 Flow Rate Measurement Process 16 Flow Rate Determination Process 17 Heating Inhibition Process

Claims (2)

[Claims] 1. A mode determination step of determining whether the operation mode before the power failure is a water supply mode to the hot water storage tank or a drainage mode from the hot water storage tank when returning from the power failure, and the mode determination step is a water supply mode. If it is determined that there is a temporary drainage step of draining from the hot water storage tank for a predetermined time, a water supply step of supplying water to the hot water storage tank after the temporary drainage step, and a water supply flow rate to the hot water storage tank in the water supply step. A flow rate measuring step of measuring, a flow rate determining step of determining whether the flow rate measured in the flow rate measuring step has reached a predetermined flow rate within a predetermined time, and if the flow rate is less than the predetermined flow rate in the flow rate determining step, it is determined that the water supply is abnormal and a heating device. A method for preventing emptying of a hot water storage type hot water supply device, which comprises a heating prohibition step of stopping the heating. 2. A mode determination step of determining whether the operation mode before the power failure was a water supply mode to the hot water storage tank or a drainage mode from the hot water storage tank when returning from the power failure, and the mode determination step is a water supply mode. If it is determined that there is a water supply to the hot water storage tank while draining water for a predetermined time, a flow rate measurement step of measuring the water supply flow rate to the hot water storage tank in the water supply and drainage step, and the flow rate measurement step. Prevention of the hot water storage type water heater having a flow rate determination step of determining whether the flow rate has reached a predetermined flow rate and a heating prohibition step of stopping the heating device as a water supply abnormality if the flow rate is less than the predetermined flow rate in the flow rate determination step. Method.