JP3382691B2 - Operation method of bypass control valve during hot water supply standby - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a bypass mixing method.
Of bypass control valve during stand-by for hot water supply of water heater
It is about the method of operation. [0002] 2. Description of the Related Art FIG.
The schematic diagram of an example of a water heater is shown. In FIG.
The burner 7 and the heat exchanger 2, which are the baking / heating mechanism, are used as a combustion unit.
Provided in the case 24 and housed in the instrument case 1
The gas nozzle 6 faces the gas inlet of the burner 7
The gas pipe 14 leading to the gas nozzle 6 has a gas supply.
Proportional valve 8 that controls supply by opening amount, and opening and closing of pipeline
And a solenoid valve 10 for performing the following operation, and the lower side of the burner 7 is provided.
Is provided with a combustion fan 13. [0003] The inlet side of the heat exchanger 2 functions as an inlet.
The water supply pipe 3 is connected, and the inlet side of the water supply pipe 3
Is a water supply via a flow sensor 9 such as a flow sensor.
It is connected to the water supply side.
The amount of water sent to the heat exchanger 2 side via the
This is detected by the sensor 9. In addition,
The water pipe 3 is provided with a heat exchanger 2 through a water supply pipe 3 from a water supply source.
Inlet temperature of a thermistor etc. that detects the temperature of water entering the side
A degree sensor 18 is provided. The outlet side of the heat exchanger 2 functions as a hot water passage.
The hot water supply pipe 11 is connected to the hot water supply pipe 11,
A tapping temperature sensor 16 such as a thermistor for detecting
The tip side of the hot water supply pipe 11 is the desired hot water supply location, in this figure
Is piped onto the sink 43, and the pipe position near the sink is
A hot water tap 12 is attached. [0005] In addition, the water supply pipe 3 communicates with the hot water supply pipe 11 for heat exchange.
A bypass passage 4 bypassing the heat exchanger 2 is provided in parallel with the heat exchanger 2.
The inlet side of the bypass passage 4 is on the water supply pipe 3 side.
And the outlet end opens and closes the bypass flow path 4
Via a bypass solenoid valve 15 functioning as a bypass control valve
The mixing part 19 is connected to the hot water supply pipe 11. In addition,
Generally, when the water heater is not burning,
The bypass electromagnetic valve 15 is in a closed state. In the water heater, heating control of the heat exchanger 2 is performed.
A control device 20 is provided.
An arithmetic circuit (not shown) is provided. Also, the control device
Reference numeral 20 denotes the incoming water temperature sensor 18 and the flow rate sensor 9
And hot water temperature sensor 16WithEach detection signal is added
The control device 20 includes a remote control having a temperature setting unit and the like.
The control device 20 is connected to each of the detection units.
Receiving the signal and the signal such as the set temperature from the remote controller 21,
The water heater is burning. That is, the control device 2
0 indicates that the hot water tap 12 is opened and the flow sensor 9 operates.
When the amount of supplied water equal to or greater than the amount of water is detected, the combustion fan 1
3 and the number of rotations of the combustion fan 13 is in a stable rotation region.
Confirm that the solenoid valve is on and open the solenoid valve 10 and the proportional valve 8.
Then, the burner 7 is ignited. Then, as described above, the ignition of the burner 7
Once done and ignited, burner combustion takes place, heat exchanger
The water passing through 2 is heated and turned into hot water.
Go through. On the other hand, it is provided in the bypass passage 4.
The bypass solenoid valve 15 is opened, and the bypass passage 4 is opened.
Water is sent to the hot water supply pipe 11 side and passes through the heat exchanger 2.
When the hot water reaches the mixing section 19, the heat exchanger 2 side
The hot water merges with the unheated water that has passed through the bypass passage 4.
Together, a hot water is created at the operating temperature, which is
Hot water is used inside. [0008] The control device 20 is activated immediately after the burner 7 is ignited.
Is the feed-forward control (the tapping temperature is detected by tapping temperature sensor 16).
Without detecting the temperature, the gas supply pattern set in advance
Control method to perform combustion in accordance with the
After that, feed is performed by PID calculation etc.
Back control (Detects hot water temperature with hot water temperature sensor 16)
The PID calculation is performed so that the tapping temperature approaches the set temperature.
To control the gas supply amount, that is, the opening amount of the proportional valve 8
Expression). [0009] However, water heaters
There are various usage patterns, such as hot water supply
After opening the tap 12 and using hot water from the hot water supply pipe 11
At first, close the hot water tap 12 and stop the hot water from the hot water pipe 11.
After a short time has passed, open the water tap 12 again
Sometimes hot water is supplied from hot water pipe 11, and hot water is supplied from hot water pipe 11.
After a long time has passed after the hot water is stopped, the hot water is re-started
Sometimes. Then, the hot water from the hot water supply pipe 11 is stopped.
Waiting time before starting hot water from hot water supply pipe 11 again
In this case, as shown in a hatched portion A in FIG.
Hot water supply pipe 11 from the outlet side of heat exchanger 2 to mixing section 19
In the last time the water heater was used,
There is still hot water that has been warmed up, and
The residual heat of the heat exchanger 2 warmed during operation is the heat exchanger 2
It is transmitted to the hot water that has stayed inside, causing a post-boiling phenomenon of the hot water,
The hot water in the heat exchanger 2 becomes even hotter.
Hot water like the tip of the hot water pipe 11 through the mixing section 19
Despite being sent to the end side, the bypass flow path 4
The bypass solenoid valve 15 is always in a closed state,
The control device 20 starts reboil based on the detection signal of the flow sensor 9.
At the beginning, burner combustion is performed, and then bypass electromagnetic
Because there is some time delay before opening valve 15,
The water from the bypass flow path 4 joins the hot water from the exchanger 2
Overshoot hotter than set temperature
Hot water flows into the sink 43 from the end of the hot water supply pipe 11 as it is.
And the user feels uncomfortable
There was a problem. In order to solve the above problem, for example,
For example, as shown in FIG.
Leave the pass solenoid valve 15 open all the time,
When opened, bypasses hot water from heat exchanger 2
Water from channel 4 is instantaneously merged and mixed without time delay
It is possible to supply hot water from the tip side of the pipe 11.
However, if this is done, the hot water tap 12 is closed and the hot water
After a long time has passed after stopping hot water from 11,
When the hot water tap 12 is opened and hot water is to be supplied again,
The hot water in the shaded area A in FIG.
It's already been cold for a long time until
Nevertheless, this cold water is further fed into the bypass channel 4.
Water from the hot water supply pipe 11
Cold undershoot water (water) with low temperature
It will be hot water, and then, like above
The user was uncomfortable and was a problem. The present invention has been made to solve the above-mentioned conventional problems.
The purpose was to stop the water heater
Regardless of the length of the waiting time until the hot water is reapplied,
Overshoot and undershoot hot water when reappearing
Suppresses hot water and allows hot water close to the set temperature
Of bypass control valve during re-watering standby of hot water heater
It is to provide a method. [0013] [MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The present invention is configured as follows. That is, the book
The invention connects the inlet and outlet of the heat exchanger of the water heater.
To provide a bypass flow path that bypasses the heat exchanger.
A bypass control valve that opens and closes the flow path
Operation of the bypass control valve while the water heater is in standby
In the law, when starting hot water supply again after the stop of hot water supply combustion,
Elapsed time from the stop of hot water supply combustion when hot water from the bar chute comes out
And the undershoot hot water comes out.
Set the time around the overtime boundary as the valve switching time
AndHot water setting temperature is high or low
If the hot water supply temperature is set to a high temperature,
Close the bypass control valve and wait for hot water
As well as bypass after re-start
The hot water supply operation is performed while the control valve is closed.
When the constant temperature is the low temperature setting,When hot water combustion stops
Measure the elapsed time of hot water combustion stop,
Until the valve switching time is reached
Open the valve and wait for hot water supply again when switching valves
After that time, close the bypass control valve and refill
It is characterized in that it stands by in preparation for the event. [0014] [0015] According to the present invention having the above-mentioned structure, the stop of the hot water supply combustion is stopped.
Hot water fuel that produces overshoot water at the start of re-watering
Elapsed time since the stop of baking and hot water of undershoot
Time around the boundary of the time elapsed since the stop of hot water supply combustion
Set as the switching time and supply hot water from when hot water combustion stops
Until the elapsed time of combustion stoppage reaches the valve switching time
Prepares for hot water re-opening by opening the bypass control valve.
Hot water that flows from the heat exchanger through the hot water path
And water from the bypass flow path mix and overflow from the hot water path
-The temperature of the hot water close to the set temperature
Hot water is discharged. The time elapsed since the stop of the hot water supply combustion was earlier.
After the valve switching time has been reached,
The temperature of hot water in the hot water path from the hot water to the bypass
At this time, the bypass control valve is closed.
To be ready for hot water again
Hot water without mixing with water from bypass channel
It is close to the set temperature from the hot water path because the hot water is discharged from the road
Hot water of hot water is poured. [0017] DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.
I do. In the description of this embodiment, the same name as the conventional example is used.
The same reference numerals are given to the same parts, and the detailed description thereof will be omitted.
FIG. 1 shows a state in which the water heater according to the present invention waits for re-watering.
The bypass control valve is controlled by the operation method of the bypass control valve
A block diagram of the control mechanism is shown. In addition, the real
The water heater of the embodiment has the same structure as the conventional water heater shown in FIG.
This embodiment is different from the conventional example.
Is a configuration of the control device 20 as shown in FIG.
While waiting for hot water, the bypass
The configuration is such that the solenoid valve 15 is switched.
You. As shown in FIG. 1, the control device 20
A solenoid valve control unit 39 and a combustion operation control unit 40.
The bypass electromagnetic valve control unit 39 includes a high / low temperature setting determination unit 30,
Ipass solenoid valve on / off command unit 31, bypass solenoid valve drive
Unit 32, a standby time measurement timer 33, and a memory unit 34,
The operation control unit 40 includes a combustion capacity calculation unit 35 and a proportional valve operation amount calculation.
Comprising a unit 36, a proportional valve driving unit 37, and a temperature deviation detecting unit 38
Have been. The high / low temperature setting determining section 30
If the set temperature of hot water supplied to temperature setting section 29 is
This is to determine whether the setting is a low setting or a low setting.
Upon receiving a signal from the temperature setting unit 29, for example, the set temperature
In case of 60 ℃ or 70 ℃, if the set temperature is high temperature setting
Judge, when the set temperature is, for example, 36 ℃ ~ 48 ℃
Determines that the set temperature is a low temperature setting, and makes these determinations.
The result is added to the bypass solenoid valve on / off command unit 31. Further, the standby time measuring timer 33 has a function of
Measure the waiting time from when it was stopped until the hot water is reapplied.
It receives the signal from the flow rate sensor 9 and
Detection signal detected by flow rate sensor 9 after hot water supply is stopped
Is turned off, and then the flow sensor 9 is turned on again
Is measured as the standby time, and the standby time is
It is added to the I-pass solenoid valve on / off command unit 31. The bypass solenoid valve on / off command section 31
The signal from the high / low temperature setting judgment unit 30 and the standby time measurement
In response to the signal from the Ima 33, the bypass solenoid valve 15
An off signal is applied to the bypass solenoid valve drive unit 32.
The set temperature of hot water supply is determined by the high /
If it is determined that the temperature is high, the bypass solenoid valve
A 15-off command signal is applied to the bypass solenoid valve drive unit 32.
In addition, the bypass solenoid valve on / off command unit 31 controls the comparison circuit.
The hot / cold setting judging section 30 sets the hot water supply.
When it is determined that the constant temperature is a low temperature setting, first,
Standby time and memo measured by the standby time measurement timer 33
Compare the valve switching time previously input to the
You. The valve switching time is determined in advance by experiments and the like.
And are individually designed for each water heater.
Heat capacity of the heat exchanger 2 and the hot water temperature and the heat exchanger 2
Difference from the hot water inside, mixing part from the outlet side of heat exchanger 2
From the time when hot water combustion stops due to the length of hot water pipe 11 up to 19, etc.
During the waiting time until hot water reappears, the hot water temperature in heat exchanger 2 and heat exchange
In the hot water supply pipe 11 from the outlet side of the exchanger 2 to the mixing section 19
The difference is how cool the hot water is,
In addition, the ambient temperature of the water heater,
Combustion condition (how many times the set temperature and how long
The temperature of the hot water in the water pipe 11
For example, before performing the combustion operation of the water heater,
Similar environment (ambient temperature) using the same type of water heater
Combustion operation under the condition of
Hot water is re-discharged at regular intervals and the temperature of such hot water is detected.
Repeat several times, what conditions (environment, water heater machine
Seeds) when the heat exchanger
Tables and graphs show how much the temperature of hot water in 2 cools down
Data, and as a result,
Time until hot water of overshoot comes out when starting hot water again
Around the boundary of the time until the undershoot hot water comes out
The time is calculated and set as the valve switching time.
is there. Also, instead of conducting the above experiment,
From various values such as the amount of heat held by the heat exchanger 2, theoretical calculation
At the start of hot water supply after the stop of hot water supply combustion.
Time to shoot hot water and undershoot hot water
Is calculated and the boundary between the two is calculated from the calculated value.
The surrounding time may be set as the valve switching time.
You. The bypass solenoid valve on / off command section 31
Is obtained as described above and input to the memory unit 34.
Added from the valve switching time and standby time measurement timer 33
Compared with the signal of the standby time, the standby time when the valve is switched
Until the time is reached, leave the bypass solenoid valve 15 open.
The standby solenoid valve on signal is
In addition to the magnetic valve drive unit 32, measured by the standby time measurement timer 33
After the standby time reaches the valve switching time, the bypass
To close the magnetic valve 15 and wait for re-hot water,
The bypass solenoid valve off signal is applied to the bypass solenoid valve driver 32.
I can. The bypass solenoid valve driving section 32 is provided with a bypass solenoid valve.
In response to a signal from the valve on / off command section 31,
This is for controlling the drive of the magnetic valve 15.
The bypass solenoid valve on signal from the on / off command unit 31
When applied to the solenoid valve drive 32, the bypass solenoid
Drive valve 15 to ON (open state) and turn on bypass solenoid valve
・ Bypass solenoid valve off signal from the off command unit 31 is bypassed
When applied to the solenoid valve drive 32, the bypass solenoid valve
15 is turned off (closed state). The combustion capacity calculation section 35 has a calculation circuit.
To calculate the combustion capacity of the water heater using an arithmetic circuit.
The set temperature signal of the temperature setting section 29 of the remote control 21
And the flow rate detection signal detected by the flow rate sensor 9 and the incoming water temperature
The incoming water temperature detection signal detected by the temperature sensor 18 always burns
It is added to the capacity calculation unit 35. The temperature deviation detection section 38 includes a comparison circuit and an arithmetic circuit
And the set temperature input to the temperature setting unit 29.
And a tapping temperature detection signal detected by tapping temperature sensor 16.
Compare and detect temperature deviation between tapping temperature and set temperature
The detection signal of the temperature deviation between the tapping temperature and the set temperature
Is added to the combustion capacity calculation unit 35. And the burning performance
The calculating unit 35 is configured to include the temperature setting unit 29, the flow rate sensor 9, and the incoming water temperature.
The signal from the sensor 18 and the signal from the temperature deviation detection unit 38 are
Then, the arithmetic circuit calculates the combustion capacity of the water heater.
Then, the calculation result is added to the proportional valve operation amount calculation unit 36. The proportional valve operation amount calculation unit 36 has a calculation circuit.
And the calculation of the combustion capacity of the water heater from the combustion capacity calculation unit 35
Based on the result, the operation amount of the gas proportional valve 8 is calculated by the arithmetic circuit.
The calculation result is added to the proportional valve drive unit 37. The proportional valve driving section 37 is provided with a proportional valve operation amount calculating section 36.
Control of the gas proportional valve 8
And is calculated by the proportional valve operation amount calculation unit 36.
Opens and closes the proportional valve 8 by the amount of operation
Controls the combustion so that the tap water temperature is almost equal to the set temperature
It is something to do. This embodiment is configured as described above.
Next, the operation will be described with reference to the flowchart of FIG.
This will be specifically described based on the following. First, in step 101,
Mocon 21 is turned on and the water heater burns.
In step 102, it is determined whether the flow sensor 9 is on.
When the flow sensor 9 is on,
At 103, the combustion operation is started. Next, at step 104
・ The set temperature of the remote control 21 is high by the low temperature setting judgment unit 30
Determines whether the temperature setting is a low temperature setting or not.
A judgment signal is added to the magnetic valve on / off command section 31 to make the set temperature
If it is determined that the temperature is the high temperature setting, then in step 105
The bypass solenoid valve 15 is turned off by the bypass solenoid valve drive unit 32
In step 104, the set temperature of the remote control 21 is set to a low temperature.
If it is determined that the
The bypass solenoid valve 15 is turned on by the solenoid valve drive unit 32. Next, at step 107, the combustion operation control unit 40
The temperature deviation detector 38 detects that the set temperature and tap water temperature
Judge whether they are equal, and set temperature and tap water temperature are almost equal
Combustion operation while controlling combustion of the water heater so that it becomes difficult
And proceed to step 109. Next, at step 109, the flow sensor 9 is turned off.
It is determined whether or not hot water is supplied when the flow sensor 9 is on.
Return to step 104 because the burner operation is continuing.
Steps 104 to 109 are repeated and the water heater
The combustion operation of is continued. Then, in step 109, the flow rate
If it is determined that the sensor 9 is off,
When 0, the combustion operation of the water heater is stopped. Then, in step 111, the data is transferred to the memory section 34.
Set the pass solenoid valve off time (valve switching time) and
At step 112, the standby time measurement timer 33 is started.
Next, at step 113, whether the bypass solenoid valve 15 is
And when the bypass solenoid valve 15 is on,
114, the bypass solenoid valve on / off command unit 31
Measurement of valve switching time and standby time input to the memory unit 34 in advance
Compare the standby time measured by the timer 33 and wait
If the time has not reached the valve switching time,
The water heater reappears with the solenoid valve 15 turned on (open).
Waiting for hot water, wait time is measured by the standby time measurement timer 33
When the standby time reaches the valve switching time,
Turn off the bypass solenoid valve 15 (closed state) at step 115 to supply hot water
Wait for hot water to reappear. In step 113,
When it is determined that the bypass solenoid valve 15 is off, that is,
When the set temperature of the water heater is set to high temperature, the bypass electromagnetic
The valve 15 remains in the OFF state and waits.
move on. Then, at step 116, the flow sensor 9 is turned off.
Return to step 102
To continue the combustion operation of the water heater.
If the water heater is not re-heated without the sensor 9 turning on,
Return to step 113 and the water heater is re-heated.
Steps 113 to 115 are performed until
Stand by in preparation for hot water supply again. That is, in step 114, the standby time is measured.
The standby time measured by the timer 33 determines the valve switching time.
When it is determined that the elapsed time has not elapsed, FIG.
As shown, when the water heater stops burning (time indicated by A in the figure)
Time when the hot water is again supplied and the combustion operation is performed again (Fig.
The waiting time until the time indicated by B) is short.
The time shown in B of the figure when the combustion operation of the water heater is started,
Since the valve switching time shown in FIG.
The state where the bypass solenoid valve 15 is kept on is continued. Then, in step 114, the standby time measurement
Standby time measured by ima 33 reaches valve switching time
When it is determined that the operation has been performed, as shown in FIG.
Then, the hot water is again supplied from the time when the hot water supply combustion is stopped as shown in FIG.
Standby until the time shown in B of the figure where the combustion operation is started
The time is long and after the valve switching time shown in C in the figure has passed
When the valve switching time shown in Fig. C has been reached.
At this point, the bypass solenoid valve 15 is turned off,
Wait until the start of hot water supply, start combustion operation by hot water supply
As a result, the bypass solenoid valve 15 is turned on again.
ing. The bypass solenoid valve 15 is turned on from the off state.
When the state is switched to, the combustion operation of the water heater starts
At the same time as trying to turn on the bypass solenoid valve 15
Also delay in ON flow rate detection and input operation of bypass solenoid valve
A slight delay occurs due to a delay or the like. According to this embodiment, as described above,
The combustion operation of the water heater is controlled by the combustion operation control unit 40 of the control device 20.
The hot water supply combustion is controlled by the bypass solenoid valve control unit 39.
Measures the elapsed time of hot water combustion stoppage from the stop,
From the time of stop until the valve switching time is reached, the bypass
Open the solenoid valve 15 and wait for the hot water heater to reheat.
Hot water heated by the previous combustion operation
When the hot water is not cooled, the hot water and bypass passage 4
From the hot water supply pipe 11
No overshoot hot water will come out from 11
Hot water with a temperature close to the temperature is supplied. Further, the elapsed time of the stoppage of hot water supply combustion is switched by a valve.
After that, the bypass solenoid valve 15 is closed.
The last hot water supply to wait for the hot water supply
A long time has elapsed since the combustion was stopped, and the
When the warm water has cooled, the bypass flow
The bypass solenoid valve 15 of the road 4 is closed,
The water from the water flow path 4 joins and mixes with the hot water passing through the hot water supply pipe 11.
Instead, the water passing through the hot water supply pipe 11
Is not further cooled by the
Hot water with a temperature close to the temperature is drawn from the hot water supply pipe 11, and
The undershoot hot water is suppressed
You. In this embodiment, the bypass solenoid valve is controlled.
A high / low temperature setting judging unit 30 is provided in the unit 39.
The set temperature input to the temperature setting section 29 of the condenser 21 is high.
If set, the bypass solenoid valve of the bypass passage 4
15 is in a closed state and is heated by the heat exchanger 2.
Hot water passes through mixing section 19 of hot water supply pipe 11
There is no merging and mixing with water from the flow path 4, which is
When the combustion operation of the water heater starts,
The bypass solenoid valve 15 of the bypass passage 4 is opened to open the bypass passage.
4 is mixed with the water from the heat exchanger 2 side
Because there is nothing to say, the water from the bypass passage 4
The temperature of hot water to be heated on the heat exchanger 2 side is increased by the amount of cooling.
It is not necessary to reduce the
Also avoid the danger of boiling inside the heat exchanger.
Can be. The present invention is not limited to the above embodiment.
Rather, various embodiments can be employed. For example, above
In the embodiment, the valve switching time is set before starting the combustion operation.
Is set in advance by experimentation, etc., and the set value is controlled.
Although input to the memory unit 34 of the device 20, the valve switching time is
The value obtained in advance before the combustion operation is started
Not always input, as shown in FIG.
Step between steps 107 and 109 on the chart
117 operation, and the combustion capacity calculation unit 35 of the control device 20
The previous combustion operation before stopping the water heater combustion operation
The amount of heat used during combustion
The result is added to the memory unit 34, and the
The bypass solenoid valve on / off command section 31 is added to the memory section 34.
Based on the value of the combustion amount obtained in the previous combustion,
4 and the hot water pipe 11, the cross-sectional area difference, the outside temperature of the water heater,
Calculate the valve switching time and switch the calculated value.
It may be set as the time. Thus, every time the water heater burns,
The heat capacity of the heat exchanger 2 is calculated by calculating the combustion capacity of the water heater at the time.
The valve switching time according to the retained heat.
If it is configured to perform variable control,
After a long time, it is sent from the heat exchanger 2 to the hot water supply pipe 11 side
The temperature of the hot water, such as how much
Set the valve switching time each time depending on the degree of drop
Because of this, the temperature is closer to the set temperature when reapplying hot water
It is possible to supply hot water. In the above embodiment, the control device 20
The low temperature setting judging section 30 sets the hot water supply temperature to 60 ° C. or 70 ° C.
When the temperature is ℃, it is determined that the temperature is high, and the set temperature is 36 to 48
At ℃, it was determined that the temperature was set to low temperature.
The setting judging unit 30 does not necessarily set the temperature to 60 ° C or 70 ° C.
Sometimes it is determined that the temperature is high, and the set temperature is 36-48 ° C.
Sometimes it is not always determined that the temperature is low,
Is determined to be a high temperature setting or determined to be a low temperature setting
The value to be set is not particularly limited. [0043] [0044] According to the present invention, after the stop of hot water supply combustion,
Hot water supply burnout at which overshooting water is generated at the start of re-hot water supply
Hot water supply with elapsed time from stoppage and undershoot hot water
Switching the time around the boundary of the elapsed time since the combustion was stopped
Set the time asThe set temperature of hot water is low
SometimesFrom when hot water combustion stops to when hot water combustion stops
Between the stop of hot water supply combustion and the valve switching time.
Keep the bypass control valve open until refilling
In order to be prepared for standby,
Overshoot where the elapsed time of firing does not reach the valve switching time
In short periods when it is expected that hot water will come out,
The path control valve remains open and the heat exchanger side
Water from the bypass flow path merges with hot water from
Overshoot hot water comes out from the end of the hot water path
Instead, hot water with a temperature close to the set temperature is supplied. Further, from the time when the hot water supply combustion is stopped, the hot water supply combustion is stopped.
After the elapsed time reaches the valve switching time, the bypass
In order to close the control valve and wait for hot water,
When the temperature of the tap water drops after the valve switching time has elapsed
Means that water from the bypass flow path is mixed with hot water
Instead, as before, the temperature of the hot water in the hot spring path has dropped
Nevertheless, the hot water is
Do not mix cold water
It is possible to prevent the undershoot
The hot water with a temperature close to the set temperature.
You. Furthermore, the set temperature of hot water supply is a high temperature setting.
Or low temperature setting.
Added the operation method of the bypass control valve.Because,Up
The operation of the bypass control valve is performed only at the time of low temperature setting,
When the hot water setting temperature is highBypass control
Because the valve is kept closedBy hot water from the heat exchanger side
No mixing of water from the path flow path, bypass flow
As much as the temperature from the water can lower the heat exchanger
It is not necessary to set the temperature of hot water to be heated higher
for(The temperature of the hot water heated by the heat exchanger is
Lower), Such as when the flow rate decreases transiently
Even avoid the danger of boiling inside the heat exchanger
And safe hot water supply becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a control mechanism that operates by a method of operating a bypass control valve while the water heater according to the present invention waits for re-watering. FIG. 2 is a flowchart showing a combustion operation of a water heater and a control operation of a bypass control valve during standby for re-watering performed by the control mechanism shown in FIG. 1; FIG. 3 is an explanatory diagram showing a difference in operation of a bypass solenoid valve due to a difference in standby time of hot water supply again. FIG. 4 is a flowchart showing another embodiment of the method of operating the bypass control valve while the water heater is waiting for re-watering. FIG. 5 is an explanatory diagram of the hot water temperature in the hot water supply pipe 11 and the heat exchanger 2 while the hot water supply unit is waiting for re-watering. FIG. 6 is an explanatory view of a bypass mixing type water heater. [Description of Signs] 2 Heat exchanger 4 Bypass flow path 9 Flow rate sensor 11 Hot water supply pipe 15 Bypass solenoid valve 30 High / low temperature setting determination unit 31 Bypass solenoid valve on / off command unit 33 Standby time measurement timer 39 Bypass solenoid valve control unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-137453 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F24H 1/10 302

Claims (1)

(57) [Claims 1] A bypass flow path which bypasses the heat exchanger by connecting a water inlet path and a hot water path of a heat exchanger of a water heater is provided. In the operation method of the bypass control valve in the standby state of hot water supply provided with the bypass control valve for opening and closing the hot water supply, the time elapsed from the stop of the hot water supply combustion when overshoot hot water is output at the start of the re-hot water supply after the stop of hot water supply combustion Set the time around the boundary between the time and the time elapsed from the stop of the hot water supply when the undershoot hot water flows out as the valve switching time, and set the hot water supply temperature to a high or low temperature setting.
If the hot water supply temperature is set to high temperature
Close the bypass control valve and wait for hot water
After the start of hot water supply
The hot water supply operation is performed while the path control valve is closed.
When the set temperature is set to a low temperature, the elapsed time from the stoppage of hot water supply combustion to the stoppage of hot water supply combustion is measured. The method of operating the bypass control valve during standby for re-watering of the water heater that closes the bypass control valve and waits for re-water supply after the valve switching time has been reached.