JPH11132563A - Method for controlling prevention of discharging of high temperature water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a state in which a discharging of hot water of high temperature is continued in respect to a set hot water feeding temperature from being continued for a long time and improve a level of sensing abnormal state. SOLUTION: In the case that a hot water feeding set temperature Ts is high and an entire water feeding amount Qt is lower than a minimum set water feeding amount Qtm (Qsm=5 littler/min.), a flow rate adjusting valve is fully closed and an amount of gas is adjusted by a gas control valve 10 so as to perform a discharged hot water temperature control. In turn, if the total amount of fed water Qt is lower than the minimum set water feeding amount Qtm (Qsm=5 litter/min.) (Qt<Qtm) and a hot water discharging temperature Th is not less than a hot water discharging intermediate set value Tho (Th>=Tho=80 deg.C), a degree of opening of the flow rate regulating valve is adjusted to perform a water feeding control and further to control the hot water discharging temperature Th.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water discharge prevention control method having a function of preventing over-flow out of a hot water supply device beyond a hot water supply capability and a function of preventing a hot water discharge.

[0002]

2. Description of the Related Art Conventionally, in a water heater provided with a function of preventing over-flow out of the water heater beyond the tapping capacity, as shown in a flowchart of FIG. (Less than 75 ° C.), the flow rate is adjusted by adjusting the opening of a flow control valve with an overflow prevention function (hereinafter simply referred to as a flow control valve), and the tap water temperature Th is set to the tap water set value Thm.
If it is lower than (e.g., 90 [deg.] C.), it is determined to be normal and the tapping operation is continued. The state where the tapping temperature Th is equal to or higher than the tapping set value Thm (90 ° C.) is a predetermined time t.
₀₁ (for example, for 2 seconds), it is determined that the hot water is supplied and the state is abnormal. The hot water supply set temperature T
When s is high (75 ° C.), the flow control valve is fully closed, the gas amount is adjusted by the gas control valve, and the tap water temperature is controlled.
If the tapping temperature Th is less than the tapping set value Thm (90 ° C.), it is determined that the tapping is normal and the tapping operation is continued. Further, the tapping temperature Th is equal to the tapping set value Thm (90 ° C.).
When the above state continues for a predetermined time t ₀₂ (for example, 60 seconds), it is determined that the hot water is supplied and the state is abnormal. Further, Japanese Patent Application Laid-Open No. 8-75246 discloses a system in which when a tapping temperature equal to or higher than a tapping set temperature has continued for a predetermined time or more, it is determined that an abnormality has occurred. Further, Japanese Patent Application Laid-Open No. 8-210700 discloses that when the tap water temperature exceeds a predetermined temperature range with respect to a set temperature in the combustion with the minimum combustion capacity based on the flow rate of water, it is determined that the state is abnormal. Things are listed.

[0003]

However, in the above conventional tapping temperature control, when the hot water supply set temperature Ts is high (75 ° C.), the flow control valve is fully closed (the flow rate is zero or more).
The tapping temperature is controlled by adjusting the amount of gas by the gas control valve, and the accuracy of tapping temperature control by the gas amount control can be maintained at a high level. Although the gas amount control is performed, regardless of the accuracy of the tapping water temperature control by the gas amount control, the water amount control is performed from the maximum flow rate to the minimum combustible water flow rate (MOQ).
At the time of a large flow rate change near the FF flow rate, there is a problem that the can body temperature becomes high for a long time due to the after-boiling inside the can, and the high-temperature hot water continues for a long time. In addition, hot water supply set temperature T
In order to avoid danger caused by continuous hot water tapping for s, temperature and time standards are set and abnormalities are detected based on these standards.However, be careful not to judge abnormalities during normal operation. Since the reference time is set long according to the actual situation, there is a problem that the level is low from the viewpoint of danger prevention.

An object of the present invention is to provide a high-temperature hot-water supply prevention control method capable of preventing a state in which high-temperature hot water continues from a set hot water supply temperature for a long time and improving the level of abnormality detection. It is.

[0005]

In order to achieve the above object, a high-temperature hot-water tapping prevention control method according to the present invention comprises a heat exchanger, a bypass path for high-passing the heat exchanger, and a burner for heating the heat exchanger. A water heater comprising a flow control valve with an overflow prevention function, a gas amount control valve for adjusting a gas amount to a burner, a water amount sensor for detecting a total water flow amount Qt, and a tap water temperature sensor for detecting a tap water temperature Th. In the above, when the total flow rate Qt is less than the minimum set flow rate Qtm and the tapping temperature Th is equal to or higher than the preset tapping intermediate set value Th, the tapping rate control is performed to control the tapping temperature Th. If the hot water supply set temperature Ts is high, the flow rate regulating valve is fully closed and the hot water supply temperature Ts is controlled. Close to large When the flow rate changes, a hot water tapping intermediate set value Tho that is lower than the hot water tapping set value is set,
Only when the tapping temperature Th becomes equal to or higher than the tapping intermediate setting value Tho, the flow rate control is performed by controlling the opening of the flow control valve, so that the tapping temperature Th can be reduced to less than the tapping intermediate setting value Tho in a short time. Thus, it is possible to eliminate the risk of determining that the operation is abnormal irrespective of normal operation. Also,
Even if the hot water supply set temperature Ts changes, the time until all the abnormalities can be detected can be unified, and the time until the abnormalities can be detected can be greatly reduced, so that the safety is significantly improved. Further, since the tapping temperature Th can be greatly reduced by controlling the flow of water through the flow control valve, safety is improved. Further, these effects are extremely effective in a large-capacity water heater having a large after-boiler. Incidentally, a heat exchanger, a bypass path for high-passing the heat exchanger, a burner for heating the heat exchanger, a flow control valve with an overflow prevention function, and a gas amount control valve for adjusting the gas amount to the burner, In a water heater provided with a water flow sensor for detecting the total water flow Qt and a hot water temperature sensor for detecting the hot water temperature Th, the total water flow Qt is the minimum set water flow Qtm.
If the temperature is lower than the first hot water setting temperature Th1, the flow control valve is fully closed, and if the hot water temperature Th is lower than the first hot water setting temperature Th1, the gas control valve is set. When the tapping temperature Th is equal to or higher than the first tapping temperature Th1, the combustion is stopped, and the tapping temperature Th drops below the second tapping temperature Th2. After confirming that, restart the combustion,
By controlling the tap water temperature by adjusting the gas amount by the gas control valve with the flow control valve fully closed, the total water flow Qt is a small amount less than the minimum set water flow, and the tap water temperature Th is the first.
When the temperature is equal to or higher than the tapping set temperature Th1, the combustion is stopped,
After confirming that the tapping temperature Th has dropped below the second tapping set temperature Th2, the combustion is restarted. Since the abnormality detection is not performed when the combustion is stopped and when the combustion is normal, the time required for all the abnormality detections is reduced. Will be the same. Further, by stopping the combustion, the tapping temperature Th can be reliably and promptly reduced to less than the second tapping set temperature Th2,
Safety is improved. In addition, it is possible to suppress the rise in the can body temperature caused by the decrease in the can body flow rate due to the control of the flow rate control valve, and to suppress the rise in the can body temperature as well as the drop in the hot water temperature by stopping the combustion. Further, after stopping the combustion, the tapping temperature Th is reduced by controlling the water flow rate by the flow control valve, and after confirming that the tapping temperature Th has dropped below the second tapping set temperature Th2, the combustion is restarted. Accordingly, the abnormality detection is not performed when the combustion is stopped and when the combustion is normal, so that the time required for all the abnormality detections is the same. In addition, by stopping the combustion and controlling the flow rate by the flow control valve, the tapping temperature Th can be reliably and promptly reduced to less than the second tapping set temperature Th2, thereby improving safety.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a water heater to which the present invention is applied will be schematically described with reference to FIG. 4. A water supply pipe 2 is connected to an inlet side of a heat exchanger 1 and a tap water pipe 3 is connected to an outlet side. , A bypass pipe 4 for bypassing the heat exchanger 1 is provided, a water supply (flow rate) sensor 5 and an incoming water temperature thermistor 6 are provided in the water supply pipe 2, and a tap water temperature thermistor 7 and an overflow prevention function are provided in the tapping pipe 3. A flow control valve 8 is provided.
Further, a burner 9 for heating the heat exchanger 1 and a control valve 10 for adjusting the amount of gas supplied to the burner 9 are provided.

A flow control operation according to a first embodiment of the present invention will be described with reference to the flowchart of FIG. The hot water supply set temperature Ts is equal to the high temperature set hot water supply temperature Tso (for example, Tso = 75).
° C) (Ts <Tso = 75 ° C), the flow rate is adjusted by adjusting the opening of a flow control valve with an overflow prevention function (hereinafter simply referred to as a flow control valve) 8 so that the tap water temperature Th is high. Hot water setting value Thm (for example, 90 ° C.) (Th <Thm = 9)
If it is 0 ° C.), it is determined that the operation is normal, and the tapping operation is continued.

Further, the tapping temperature Th is set to a high temperature tapping value Thm.
If the continuation time t in the state of (Th ≧ Thm = 90 ° C.) continues for a predetermined time t ₀ (for example, 2 seconds) or more (t ≧ t ₀ ), it is determined that the hot water is discharged and that the state is abnormal. I do. Also, the tapping temperature Th is equal to or higher than the high-temperature tapping set value Thm (T
h ≧ Thm = 90 ° C.), the state remains for a predetermined time t ₀
If the processing is completed in less than (2 seconds) (t <t ₀ ), it is determined that the state is normal.

Next, when the hot water supply set temperature Ts is high and equal to the high temperature set hot water supply temperature Tso (Ts = Tso = 75 ° C.),
The total flow rate Qt detected by the flow rate sensor 5 is equal to or greater than the minimum set flow rate Qtm (for example, Qsm = 5 liters / min.) (Qt ≧
Qtm), the flow control valve 8 is fully closed, the gas control valve 10 adjusts the gas amount to control the tapping temperature, and the tapping temperature Th is lower than the high temperature tapping set value Thm (for example, 90 ° C.) (Th. If <Thm = 90 ° C.), it is determined to be normal, and the tapping operation is continued as it is.

The total water flow Qt is the minimum set water flow Qtm (Qsm
= 5 liters / min.) (Qt <Qtm), the tapping temperature Th is less than the tapping intermediate set value Tho (Th <Th = 80).
° C), the flow control valve 8 is fully closed, the gas control valve 10 adjusts the gas volume to control the tapping temperature, and the tapping temperature Th is lower than the high temperature tapping set value Thm (eg, 90 ° C) (Th). If <Thm = 90 ° C.), it is determined to be normal, and the tapping operation is continued as it is.

On the other hand, the total flow rate Qt is equal to the minimum set flow rate Qtm.
(Qsm = 5 liters / min.) (Qt <Qtm) and the tapping temperature Th is equal to or higher than the tapping intermediate set value Tho (Th ≧ Th = 8)
If the temperature is 0 ° C.), the flow rate is controlled by adjusting the opening of the flow control valve 8 to control the tapping temperature Th, and the tapping temperature Th is lower than the high-temperature tapping set value Thm (for example, 90 ° C.) (Th < Thm
= 90 ° C), it is determined to be normal, and the tapping operation is continued.

Similarly, the tapping temperature Th is equal to the hot tapping set value T.
hm (90 ° C.) or more (Th ≧ Thm) for a predetermined time t ₀
(2 seconds), it is determined that the hot water is discharged and the state is abnormal. Even if the tapping temperature Th is equal to or higher than the high temperature tapping set value Thm (90 ° C.), if the state is completed within a predetermined time t ₀ (2 seconds), it is determined that the state is normal.

According to this configuration, the set hot water supply temperature Ts is high and the set hot water supply temperature Tso is high (Ts = Tso = 75).
° C), the maximum combustible water flow is turned off from the maximum flow rate
At the time of a large flow rate change near the flow rate, the high temperature hot water set value T
Hot water intermediate set value Tho which is lower than hm (90 ° C)
(80 ° C), and the tapping temperature Th is set to the tapping intermediate set value T.
Only when the temperature becomes ho (80 ° C.) or more, the flow rate is controlled by controlling the opening of the flow control valve.
h can be reduced to less than the hot water supply intermediate set value Tho (80 ° C.), and it is possible to eliminate the danger of being determined as abnormal regardless of normal operation. Further, even if the hot water supply set temperature Ts changes, the time until all the abnormalities can be detected can be unified, and the time until the abnormalities can be detected can be greatly reduced, so that the safety is significantly improved. The tap temperature T
Since h can be greatly reduced by controlling the flow of water through the flow control valve, safety is improved. Further, these effects are extremely effective in a large-capacity water heater having a large after-boiler.

The flow control operation of the second embodiment will be described with reference to the flowchart of FIG.
If s is lower than the high temperature set hot water supply temperature Tso (for example, Tso = 75 ° C.) (Ts <Tso = 75 ° C.), the opening degree of the flow control valve 8 is adjusted to adjust the amount of water flow, and the tapping temperature Th is set to the high temperature tapping temperature. Less than the set value Thm (for example, 90 ° C.) (Th <Thm = 90)
° C), it is determined to be normal and the tapping operation is continued. Also, the tapping temperature Th is equal to the high temperature tapping set value Thm.
If the continuation time t in the state of (Th ≧ Thm = 90 ° C.) continues for a predetermined time t ₀ (for example, 2 seconds) or more (t ≧ t ₀ ), it is determined that the hot water is discharged and that the state is abnormal. I do. Also, the tapping temperature Th is equal to or higher than the high-temperature tapping set value Thm (T
h ≧ Thm = 90 ° C.), the state remains for a predetermined time t ₀
If the processing is completed in less than (2 seconds) (t <t ₀ ), it is determined that the state is normal.

Next, when the hot water supply set temperature Ts is high and equal to the high temperature set hot water supply temperature Tso (Ts = Tso = 75 ° C.),
The total water flow Qt is the minimum set water flow Qtm (for example, Qsm = 5
Liter / min.) Or more (Qt ≧ Qtm), the flow control valve 8 is fully closed, the gas control valve 10 is used to control the gas flow, and the tapping temperature is controlled. (Eg, 90 ° C.) (Th <Thm = 90
° C), it is determined to be normal and the tapping operation is continued.

The total flow rate Qt is less than the minimum set flow rate Qtm (for example, Qsm = 5 liters / min.) (Qt <Qt).
m), the first hot water setting temperature Th1 (for example, Th1 = 8
5 ° C), and compare the tapping temperature Th with the tapping temperature Th.
Is lower than the first hot water set temperature Th1 (Th <Th1 = 85)
° C), the flow control valve 8 is fully closed and the gas control valve 10
The tapping temperature is controlled by adjusting the amount of gas.

On the other hand, the tapping temperature Th is equal to the first tapping set temperature Th1.
When the above condition is satisfied (Th ≧ Th1 = 85 ° C.), the combustion is stopped, and the tapping temperature Th becomes the first tapping set temperature Th1.
Lower second hot water set temperature Th2 (for example, Th2 = 80
° C), combustion is resumed,
The flow control valve 8 is fully closed, the gas control valve 10 controls the gas amount to control the tapping temperature, and the tapping temperature Th is lower than the hot tapping value Thm (for example, 90 ° C.) (Th <Thm =
If it is 90 ° C.), it is determined to be normal, and the tapping operation is continued as it is.

If the can body temperature Tk is detected and exceeds a preset can body maximum temperature Tko (for example, Tko = 90 ° C.), the combustion is stopped and the can body temperature Tk is reduced to the can body maximum temperature Tko. When the temperature falls below (90 ° C.), the combustion may be restarted to control the tapping temperature.

According to this configuration, the total water flow Qt is a small amount less than the minimum set water flow Qtm (5 liter / min.),
Hot water temperature Th is the first hot water set temperature Th1 (Th1 = 85 ° C.)
If the above is the case, the combustion is stopped, and after confirming that the tapping temperature Th has dropped below the second tapping set temperature Th2 (Th2 = 80 ° C.), the combustion is restarted. Since abnormality detection is not performed during normal times, the time required for all abnormality detections is the same. Further, by stopping the combustion, the tapping temperature Th can be reliably and promptly reduced to less than the second tapping set temperature Th2 (Th2 = 80 ° C.), thereby improving safety. In addition, it is possible to suppress the rise in the can body temperature caused by the decrease in the can body flow rate due to the control of the flow rate control valve, and to suppress the rise in the can body temperature as well as the drop in the hot water temperature by stopping the combustion. Further, these effects are extremely effective in a large-capacity water heater having a large after-boiler.

Next, the flow control operation of the third embodiment will be described with reference to the flowchart of FIG.
In the control operation of the embodiment, when the total flow rate Qt is a small amount less than the minimum set flow rate Qtm (5 liters / min.) And the tapping temperature Th is equal to or higher than the first tapping temperature Th1 (Th1 = 85 ° C.). After stopping the combustion, the flow control valve 8 controls the flow rate of water to lower the tapping temperature Th, and the tapping temperature T
After confirming that h has dropped below the second hot water set temperature Th2 (Th2 = 80 ° C.), combustion is restarted, the flow control valve 8 is fully closed, and the gas amount is adjusted by the gas control valve 10 to control the hot water. It controls temperature.

According to this configuration, the total water flow Qt is a small amount less than the minimum set water flow Qtm (5 liter / min.),
Hot water temperature Th is the first hot water set temperature Th1 (Th1 = 85 ° C.)
If it is above, the combustion is stopped, the flow rate is controlled by the flow control valve to lower the tapping temperature Th, and the tapping temperature Th
After confirming that the temperature has dropped to below the second hot water set temperature Th2 (Th2 = 80 ° C.), the combustion is restarted. The time required is the same. Also,
By stopping the combustion and controlling the amount of water flow through the flow control valve, the tapping temperature Th can be reliably and promptly reduced to less than the second tapping set temperature Th2 (Th2 = 80 ° C.), thereby improving safety. I do. Further, these effects are extremely effective in a large-capacity water heater having a large after-boiler.

The temperature of the can body Tk is detected, and when the temperature exceeds a predetermined can body upper limit temperature Tko (for example, Tko = 90 ° C.), the combustion is stopped and the flow rate is controlled by a flow control valve. Alternatively, when the can body temperature Tk falls below the can body upper limit temperature Tko (90 ° C.), the combustion may be restarted to control the tapping temperature. In the above embodiment, the set hot water supply temperature that can be set is Tso = 75 ° C., but this is given as an example, and it goes without saying that it can be set arbitrarily. Also, for example, the set temperature T
If s can be set to a higher temperature, such as Ts = 80 ° C., the tapping temperature T by the flow control valve is set at Ts> Tso = 75 ° C.
h or the control of the tapping temperature Th by the gas control valve may be switched.

[0023]

Since the present invention is configured as described above, it has the following effects. When the total flow rate Qt is less than the minimum set flow rate Qtm and the tapping temperature Th is equal to or higher than the preset tapping intermediate setting value Tho, the tapping temperature Th is controlled by controlling the tapping rate while the tapping temperature Th is set at the tapping intermediate setting. Value T
If it is less than ho, the flow regulating valve is fully closed, and the tapping temperature Th is controlled by the gas amount control.
At the time of a large flow rate change near the FF flow rate, a hot-water tapping intermediate set value Tho that is lower than the high-temperature hot-water tapping set value is set, and only when the tapping temperature Th becomes equal to or higher than the hot-water tapping set value Tho,
Since the flow rate is controlled by controlling the opening of the flow control valve,
The tapping temperature Th can be reduced to less than the tapping intermediate set value Tho in a short time, and it is possible to eliminate the possibility of determining that the tapping is abnormal regardless of normal operation. Further, even if the hot water supply set temperature Ts changes, the time until all the abnormalities can be detected can be unified, and the time until the abnormalities can be detected can be greatly reduced, so that the safety is significantly improved. Further, since the tapping temperature Th can be greatly reduced by controlling the flow of water through the flow control valve, safety is improved. When the total flow rate Qt is less than the minimum set flow rate Qtm and the tapping temperature Th is the first
When the temperature is equal to or higher than the hot water set temperature Th1, the combustion is stopped, and after confirming that the hot water temperature Th has dropped below the second hot water set temperature Th2, the combustion is restarted, and the flow control valve is fully closed.
By controlling the tap water temperature by adjusting the gas amount by the gas control valve, when the total water flow Qt is a small amount less than the minimum set water flow and the tap water temperature Th is equal to or higher than the first tap water set temperature Th1, combustion is performed. Is stopped, and after confirming that the tapping temperature Th has dropped below the second tapping set temperature Th2, the combustion is restarted. The time required for detection is the same. In addition, by stopping the combustion, the tapping temperature Th can be reliably and promptly reduced to less than the second tapping temperature Th2, thereby improving safety. Also,
The rise in the can body temperature caused by the decrease in the can body flow rate due to the control of the flow control valve can be suppressed together with the drop in the hot water temperature and the rise in the can body temperature due to the stop of combustion. further,
After stopping the combustion, the flow rate is controlled by the flow control valve to lower the tapping temperature Th, and after confirming that the tapping temperature Th has dropped below the second tapping set temperature Th2, the combustion is restarted. Since abnormality detection is not performed at the time of combustion stoppage and at the time of normal operation, the time required for all abnormality detections is the same. In addition, by stopping the combustion and controlling the flow rate by the flow control valve, the tapping temperature Th can be reliably and promptly reduced to less than the second tapping set temperature Th2, thereby improving safety. Further, these effects are extremely effective in a large-capacity water heater having a large after-boiler.

[Brief description of the drawings]

FIG. 1 is a flowchart of a first embodiment of temperature control according to the present invention.

FIG. 2 is a flowchart of a second embodiment of the temperature control according to the present invention.

FIG. 3 is a flowchart of a third embodiment of the temperature control according to the present invention.

FIG. 4 is a schematic configuration diagram showing an example of a water heater to which the present invention is applied.

FIG. 5 is a flowchart of a conventional temperature control.

[Explanation of symbols]

Reference Signs List 1 heat exchanger, 2 water supply pipe, 3 tap water pipe, 4 bypass pipe, 5 water quantity (flow rate) sensor, 6 incoming water temperature thermistor, 7
Hot water temperature thermistor 8 (with overflow prevention function) flow control valve, 9 burner, 1
0 Gas control valve

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Eiichi Tsuji 93, Edocho, Chuo-ku, Kobe-shi, Hyogo Pref.

Claims (3)

[Claims] 1. A heat exchanger, a bypass passage for high-passing the heat exchanger, a burner for heating the heat exchanger, a flow regulating valve with an overflow prevention function, and a gas amount control for adjusting a gas amount to the burner. In a water heater provided with a valve, a water flow sensor for detecting the total water flow Qt, and a hot water temperature sensor for detecting the hot water temperature Th, when the total water flow Qt is less than the minimum set water flow Qtm,
When the tapping temperature Th is equal to or higher than the preset tapping intermediate setting value Tho, the flow rate control is performed to control the tapping temperature Th. On the other hand, if the tapping temperature Th is less than the tapping intermediate setting value Tho,
The flow control valve is fully closed and the tapping temperature Th is controlled by gas amount control.
A hot water tapping prevention control method characterized by controlling the temperature. 2. A heat exchanger, a bypass passage for high-passing the heat exchanger, a burner for heating the heat exchanger, a flow control valve with an overflow prevention function, and a gas amount control for adjusting a gas amount to the burner. In a water heater provided with a valve, a water flow sensor for detecting the total water flow Qt, and a hot water temperature sensor for detecting the hot water temperature Th, if the total water flow Qt is less than the minimum set water flow Qtm, the first hot water supply is performed. The set temperature Th1 and the second set temperature Th2 are set. When the set temperature Th is lower than the first set temperature Th1, the flow control valve is fully closed and the gas amount is adjusted by the gas control valve to adjust the set temperature. On the other hand, when the tapping temperature Th is equal to or higher than the first tapping temperature Th1, the combustion is stopped, and after confirming that the tapping temperature Th has dropped below the second tapping temperature Th2, the combustion is restarted. , With the flow control valve fully closed and the gas control valve Hot tapping prevention control method which is characterized in that the hot water temperature control by adjusting the higher gas amount. 3. After stopping the combustion, the flow rate is controlled by a flow control valve to lower the tapping temperature Th, and the tapping temperature Th
3. The high-temperature hot-water tapping prevention control method according to claim 2, wherein the combustion is restarted after confirming that the temperature has dropped below the second hot-water tapping set temperature Th2.