JPH07174408A - Method for operating bypass control valve during standby for re-supply of hot water in hot water supplier - Google Patents

Abstract

PURPOSE:To provide a method of operation of a bypass control valve in standby for re-supply of hot water of a hot water supplier, the hot water supplier being capable of restricting supply of overshooted and undershooted hot water in starting of the re-supply of hot water after interruption of combustion. CONSTITUTION:A bypass splenoid valve control unit 39 is provided in a controller 20 of a hot water supplier, the unit including a high temperature/low temperature setting judging part 30, a bypass solenoid valve on/off instruction part 31, a bypass solenoid valve driving part 32, a standby time measurement timer 33, and a memory part 34. The bypass solenoid valve on/off instruction part 31 compares valve changeover time inputted into the memory part 34 with a lapse time since interruption of hot water supply combustion measured by the standby measurement timer 33. An instruction is issued such that the bypass solenoid valve 15 is opened and is set to standby for re-supply of hot water till the lapse time reaches the valve changeover time while the bypass solenoid valve is closed and is set to standby for re-supply of hot water after the lapse time measured by the waiting time measurement timer 33 reaches the valve changeover time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a bypass control valve while a hot water supply device of a bypass mixing system is on standby for re-hot water.

[0002]

2. Description of the Related Art FIG. 6 is a schematic view showing an example of a bypass mixing type water heater. In the same figure, the burner 7 which is a combustion heating mechanism and the heat exchanger 2 are provided in the combustion unit case 24 and housed in the instrument case 1, and the gas nozzle 6 is arranged to face the gas inlet of the burner 7. The gas pipe 14 communicating with the gas nozzle 6 is provided with a proportional valve 8 for controlling the gas supply amount by the valve opening amount and a solenoid valve 10 for opening and closing the pipe line, and on the lower side of the burner 7. A combustion fan 13 is provided.

A water supply pipe 3 functioning as a water inlet is connected to the inlet side of the heat exchanger 2, and the inlet side of the water supply pipe 3 is connected to a water supply source such as tap water via a flow sensor 9 such as a flow sensor. The flow rate sensor 9 detects the amount of water sent from the water supply source such as tap water to the heat exchanger 2 side through the water supply pipe 3. Further, the heat exchanger 2 is connected to the water supply pipe 3 through the water supply pipe 3 from the water supply source.
An incoming water temperature sensor 18 such as a thermistor for detecting the temperature of the incoming water is provided.

A hot water supply pipe 11 functioning as a hot water discharge passage is connected to the outlet side of the heat exchanger 2, and a hot water supply temperature sensor 16 such as a thermistor for detecting the hot water discharge temperature is provided in the hot water supply pipe 11. The tip end side of the hot water supply pipe 11 is piped to a desired hot water supply place, which is a sink 43 in this figure, and a hot water supply plug 12 is attached to a pipe position near the sink.

Further, a bypass passage 4 which communicates with the water supply pipe 3 and the hot water supply pipe 11 and bypasses the heat exchanger 2 is arranged in parallel with the heat exchanger 2, and the inlet side of the bypass passage 4 is supplied with water. The outlet end is connected to the pipe 3 side, and is connected to the hot water supply pipe 11 at the mixing portion 19 via a bypass solenoid valve 15 that functions as a bypass control valve that opens and closes the bypass flow path 4. In addition,
Generally, when the water heater is not burning, the bypass solenoid valve 15 is closed.

A controller 20 for controlling heating of the heat exchanger 2 and the like is provided in the water heater, and the controller 20 is provided with an arithmetic circuit (not shown). Further, the control device 20 is added with respective detection signals of the inlet water temperature sensor 18, the flow rate sensor 9, the hot water temperature sensor 16, and the bypass control valve 15. The control device 20 has a temperature setting unit. A remote controller 21 having the above components is connected, and the control device 20 receives the detection signals and signals such as the set temperature from the remote controller 21 and performs the combustion operation of the water heater. That is, the control device 20
Confirms that the combustion fan 13 is rotated when the hot water supply plug 12 is opened and the amount of supplied water equal to or greater than the amount of working water is detected by the flow rate sensor 9, and that the rotation speed of the combustion fan 13 is within the stable rotation region. Then, the solenoid valve 10 and the proportional valve 8 are opened, and the burner 7 is ignited.

When the burner 7 is ignited and ignited as described above and burner combustion is performed, the water passing through the heat exchanger 2 is heated to hot water, and this hot water flows through the hot water supply pipe 11. Go through. On the other hand, on the other hand, the bypass solenoid valve 15 provided in the bypass passage 4 is opened, and the bypass passage 4 is opened.
When the water from the heat exchanger 2 is sent to the hot water supply pipe 11 side and the hot water passing through the heat exchanger 2 reaches the mixing section 19, the hot water from the heat exchanger 2 side passes through the bypass passage 4 and is not heated. Combined and mixed to produce hot water at the working temperature, which is the sink 43
It is used by tapping hot water inside.

Immediately after the burner 7 is ignited, the control device 20 performs feedforward control (a control method in which combustion is performed according to a preset gas amount supply pattern without detecting the discharge hot water temperature sensor 16). After that, feedback control is performed by PID calculation or the like by the arithmetic circuit (the hot water temperature sensor 16 detects the hot water temperature, and the PID calculation is performed so that the hot water temperature approaches the set temperature, that is, the proportional valve 8 is opened. The method of controlling the valve amount) is performed.

[0009]

However, there are various usage patterns in the use of the hot water heater, for example, after the hot water tap 12 is opened and hot water discharged from the hot water supply pipe 11 is used, the hot water tap 12 is once used. The hot water supply pipe 11 may be closed by closing the hot water supply pipe 11, and after a short time, the hot water supply tap 12 may be opened again to perform hot water supply from the hot water supply pipe 11. After a certain amount of time has passed, hot water may be discharged again.

When the waiting time from the stop of hot water discharge from the hot water supply pipe 11 to the restart of hot water discharge from the hot water supply pipe 11 is short, as shown by the hatched portion A in FIG.
Hot water supply pipe 11 from the outlet side of the heat exchanger 2 to the mixing section 19
The hot water that was warmed by the combustion operation of the water heater when the water heater was used last time remains inside, and the residual heat of the heat exchanger 2 that was warmed during the last combustion operation is the heat exchanger 2.
It is transmitted to the hot water staying inside and the after-boiling phenomenon occurs.
The hot water in the heat exchanger 2 becomes even hotter, and when the hot water is again discharged, such hot water is sent to the tip side of the hot water supply pipe 11 via the mixing portion 19, but the bypass passage 4
The bypass solenoid valve 15 of is always closed,
Since the control device 20 determines from the detection signal of the flow rate sensor 9 the start of re-evaporation, burner combustion is performed, and then the bypass solenoid valve 15 is opened, there is a slight delay, so the heat exchanger. The hot water from the bypass flow path 4 does not join and mix with the hot water from the 2 side, and hot water having an overshoot that is higher than the set temperature is discharged from the tip side of the hot water supply pipe 11 into the sink 43 as it is. Had the problem of feeling uncomfortable.

In order to solve the above problem, for example, as shown in FIG. 5 (b), the bypass solenoid valve 15 of the bypass passage 4 is kept open and the hot water tap 12 is opened. At times, it is possible to mix the hot water from the heat exchanger 2 side with the water from the bypass flow path 4 instantaneously without time delay and let the hot water come out from the tip side of the hot water supply pipe 11. Then, close the hot water tap 12 and
After a long time has passed after stopping the hot water from 11
When the hot-water tap 12 is opened and hot water is to be discharged again, the hot water in the shaded area A in FIG. 5 (b) has already been cooled due to the previous combustion operation and the long time until the hot water is again discharged. Despite this, since the water from the bypass passage 4 merges and mixes with this cold hot water, cold undershoot hot water (water) having a temperature lower than the set temperature is discharged from the hot water supply pipe 11. In that case, the user feels uncomfortable as in the above case, which is a problem.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is, regardless of the length of the waiting time from when the water heater is stopped to when hot water is discharged again,
An object of the present invention is to provide a method for operating a bypass control valve during standby for re-emergence of a water heater that can suppress over-shooting and under-shooting hot water from being discharged during re-melting, and discharge hot water close to a set temperature.

[0013]

In order to achieve the above object, the present invention is constructed as follows. That is, the present invention provides a bypass flow path that bypasses the heat exchanger by communicating the inlet and outlet channels of the heat exchanger of the water heater, and a bypass control valve that opens and closes the flow path in the bypass flow path. In the operation method of the bypass control valve while waiting for re-emergence of the provided water heater, overshoot hot water is generated at the start of re-emergence after the stop of hot water combustion. Elapsed time after hot water combustion is stopped and undershoot hot water is emitted. The time around the boundary of the elapsed time from the hot water supply combustion stop is set as the valve switching time, the elapsed time from the hot water supply combustion stop to the hot water supply combustion stop is measured, and the time from the hot water supply combustion stop to the valve switching time is reached. It is characterized in that the bypass control valve is opened and waits for re-hot water, and after the valve switching time is reached, the bypass control valve is closed and waits for re-hot water. It is.

It is also a characteristic feature of the present invention to judge whether the set temperature of the hot water supply is a high temperature setting or a low temperature setting, and to perform the operation method of the bypass control valve when it is the low temperature setting. ing.

[0015]

In the present invention having the above-described structure, the elapsed time from the hot water supply combustion stop in which overshooting hot water comes out and the undershoot hot water comes out from the hot water supply combustion stop after restarting hot water supply after the stop of hot water supply combustion The time around the boundary of is set as the valve switching time, and the bypass control valve is opened to prepare for re-hot water from the time when hot water supply combustion is stopped until the elapsed time for hot water supply combustion stop reaches the valve switching time. , The hot water from the heat exchanger side that flows through the hot water passage and the water from the bypass flow passage are mixed, and there is no overshoot of hot water coming from the hot water passage. To be done.

Further, after the elapsed time from the stop of hot water supply combustion reaches the valve switching time, the temperature of the hot water in the hot water outlet passage from the outlet side of the heat exchanger to the bypass flow passage communicating portion is low. However, at this time, since the bypass control valve is closed and kept in standby in preparation for re-hot water, hot water from the heat exchanger side is discharged from the hot water discharge passage without being mixed with water from the bypass flow passage. In addition, hot water having a temperature close to the set temperature is discharged from the hot water passage.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same reference numerals will be given to the same names as those in the conventional example, and the detailed description thereof will be omitted.
FIG. 1 is a block diagram of a control mechanism for controlling the bypass control valve by the operation method of the bypass control valve in the hot water supply standby for hot water supply according to the present invention. The water heater of the present embodiment has the same configuration as the conventional water heater shown in FIG. 6, and the characteristic of the present embodiment that is different from the conventional water heater is that the control device 20 is as shown in FIG. The configuration is such that the bypass solenoid valve 15 is switched according to the length of the hot-spring re-waiting time while the hot-water heater is waiting for the hot-water re-hot.

As shown in FIG. 1, the control device 20 has a bypass solenoid valve control section 39 and a combustion operation control section 40. The bypass solenoid valve control section 39 includes a high temperature / low temperature setting determination section 30 and a bypass. It has a solenoid valve on / off command unit 31, a bypass solenoid valve drive unit 32, a standby time measurement timer 33, a memory unit 34, the combustion operation control unit 40, a combustion capacity calculation unit 35, a proportional valve operation amount calculation unit 36, It is configured to have a proportional valve drive unit 37 and a temperature deviation detection unit 38.

The high temperature / low temperature setting determination unit 30 determines whether the set temperature of the hot water supplied to the temperature setting unit 29 of the remote controller 1 is the high temperature setting or the low temperature setting.
In response to a signal from the temperature setting unit 29, for example, the set temperature
If it is 60 ℃ or 70 ℃, it is judged that the set temperature is the high temperature setting, and if the set temperature is, for example, 36 ℃ to 48 ℃, it is judged that the set temperature is the low temperature setting. Added to the bypass solenoid valve on / off command section 31.

The waiting time measuring timer 33 measures the waiting time from when the hot water supply is once stopped until the hot water is discharged again, and receives a signal from the flow rate sensor 9,
After the hot water supply is stopped once, the detection signal detected by the flow rate sensor 9 is turned off, and then the time until the flow rate sensor 9 is turned on again is measured as the standby time, and the standby time is sequentially commanded to bypass the solenoid valve. Add to part 31.

The bypass solenoid valve on / off command section 31 receives the signal from the high temperature / low temperature setting determination section 30 and the signal from the standby time measuring timer 33, and turns on / off the bypass solenoid valve 15.
An off signal is added to the bypass solenoid valve drive unit 32, and when the high temperature / low temperature setting determination unit 30 determines that the set temperature of hot water is the high temperature setting, the bypass solenoid valve is operated.
A 15-off command signal is applied to the bypass solenoid valve drive unit 32.
Further, the bypass solenoid valve on / off command unit 31 has a comparison circuit, and when the high temperature / low temperature setting determination unit 30 determines that the set temperature of hot water supply is the low temperature setting, first,
The standby time measured by the standby time measurement timer 33 is compared with the valve switching time input in advance in the memory unit 34.

Note that the valve switching time is obtained in advance by experiments or the like, and the amount of heat possessed by the heat exchanger 2, which is individually designed for each water heater, the outlet temperature and the heat exchanger 2
The difference from the temperature of the hot water inside, the mixing part from the outlet side of the heat exchanger 2
Depending on the length of the hot water supply pipe 11 up to 19, the hot water temperature in the heat exchanger 2 and the hot water supply pipe 11 from the outlet side of the heat exchanger 2 to the mixing unit 19 during the waiting time from the stop of hot water supply combustion to the re-emergence of hot water. It is different how much the hot water inside gets cooled,
In addition, the way the temperature of the hot water falls in the hot water supply pipe 11 varies depending on the ambient temperature of the water heater, the combustion state until the hot water combustion is stopped (how many times the set temperature is set, and how long the hot water is burned). , For example, using the same type of water heater before performing the combustion operation of the water heater, the same environment (ambient temperature)
The combustion operation is performed under the condition that the hot water supply is restarted and the hot water is discharged again at regular intervals, and such hot water temperature detection is repeated several times to determine what conditions (environment, water heater model Etc.) how much waiting time elapses before the hot water temperature in the heat exchanger 2 cools down as various data such as tables and graphs. The time around the boundary between the time until hot water for overshoot and the time for hot water for undershoot is obtained, and is set as the valve switching time.

Further, instead of conducting the above experiment,
From various values such as the amount of heat possessed by the heat exchanger 2, the time until the overshoot hot water comes out and the time until the undershoot hot water comes out are calculated by the theoretical calculation at the time of re-hot spring start after the hot water supply combustion stop However, the time around the boundary between the two may be set as the valve switching time from the calculated value.

The bypass solenoid valve on / off command section 31 compares the valve switching time, which is obtained as described above and is input to the memory section 34, with the standby time signal added from the standby time measuring timer 33. Then, until the standby time reaches the valve switching time, the bypass solenoid valve 15 is opened and the standby time is measured by the standby time measurement timer 33 so that the bypass solenoid valve ON signal is added to the bypass solenoid valve drive unit 32. After the standby time reaches the valve switching time, the bypass solenoid valve 15 is closed to wait for re-hot water,
A bypass solenoid valve OFF signal is applied to the bypass solenoid valve drive unit 32.

The bypass solenoid valve drive unit 32 receives the signal from the bypass solenoid valve on / off command unit 31 and controls the drive of the bypass solenoid valve 15. When the bypass solenoid valve ON signal is applied to the bypass solenoid valve drive unit 32, the bypass solenoid valve 15 is driven to the ON state (open state), and the bypass solenoid valve ON / OFF command unit 31 bypasses the bypass solenoid valve OFF signal. When added to solenoid valve drive 32, bypass solenoid valve
It drives 15 off (closed state).

The combustion capacity calculation unit 35 has a calculation circuit for calculating the combustion capacity of the water heater by the calculation circuit, and sets the temperature signal of the temperature setting unit 29 of the remote controller 21 and the flow rate sensor. The flow rate detection signal detected at 9 and the incoming water temperature detection signal detected by the incoming water temperature sensor 18 are constantly added to the combustion capacity calculation unit 35.

The temperature deviation detection unit 38 has a comparison circuit and an arithmetic circuit, and compares the set temperature input to the temperature setting unit 29 with the hot water temperature detection signal detected by the hot water temperature sensor 16. The temperature deviation between the tapping temperature and the set temperature is detected, and a detection signal of the temperature deviation between the tapping temperature and the set temperature is added to the combustion capacity calculation unit 35. Then, the combustion capacity calculation unit 35 receives the signals from the temperature setting unit 29, the flow rate sensor 9, the incoming water temperature sensor 18 and the signal from the temperature deviation detection unit 38, and calculates the combustion capacity of the water heater by the calculation circuit. Calculation is performed, and the calculation result is added to the proportional valve operation amount calculation unit 36.

The proportional valve operation amount calculation unit 36 has an operation circuit, and receives the operation result of the combustion capacity of the water heater from the combustion capacity operation unit 35, the operation amount of the proportional valve 8 of gas is calculated by the operation circuit. Calculation is performed and the calculation result is added to the proportional valve drive unit 37.

The proportional valve drive unit 37 includes a proportional valve operation amount calculation unit 36.
The proportional valve 8 is controlled to be driven by the gas in response to the calculation result from the control valve, and the proportional valve 8 is opened and closed by the operation amount obtained by the proportional valve operation amount calculation unit 36, whereby the combustion of the water heater is performed. Is controlled so that the hot water outlet temperature is substantially equal to the set temperature.

The present embodiment is configured as described above, and its operation will be described below with reference to the flow chart of FIG. 2 and FIG.
It will be specifically described based on. First, in step 101, the remote controller 21 is turned on so that the combustion operation of the water heater is performed. In step 102, it is determined whether the flow rate sensor 9 is on. If the flow rate sensor 9 is on, step
At 103, the combustion operation starts. Next, in step 104, the high temperature / low temperature setting determination unit 30 determines whether the set temperature of the remote controller 21 is the high temperature setting or the low temperature setting, and adds a determination signal to the bypass solenoid valve on / off command unit 31, When it is determined that the set temperature is the high temperature setting, the bypass solenoid valve driving unit 32 turns off the bypass solenoid valve 15 in step 105, and when it is determined in step 104 that the set temperature of the remote controller 21 is the low temperature setting, In step 106, the bypass solenoid valve drive unit 32 turns on the bypass solenoid valve 15.

Next, in step 107, the combustion operation control unit 40
The temperature deviation detection unit 38 determines whether or not the set temperature and the hot water temperature are substantially equal to each other, and continues the combustion operation while performing the combustion control of the water heater so that the set temperature and the hot water temperature are approximately equal to each other. move on.

Next, in step 109, it is judged whether or not the flow sensor 9 is off. When the flow sensor 9 is on, the combustion operation of the water heater is continued, so the process returns to step 104, and steps 104 to 109 are executed. Repeatedly, the burning operation of the water heater is continued. When it is determined in step 109 that the flow sensor 9 is off, step 11
At 0, stop the combustion operation of the water heater.

Then, in step 111, the bypass solenoid valve off time (valve switching time) is set in the memory section 34, and in step 112 the standby time measuring timer 33 is started.
Next, in step 113, determine whether the bypass solenoid valve 15 is on, and if the bypass solenoid valve 15 is on, step
At 114, the bypass solenoid valve on / off command unit 31 compares the valve switching time previously input to the memory unit 34 with the standby time measured by the standby time measuring timer 33, and the standby time reaches the valve switching time. If not, the bypass solenoid valve 15 is kept on (opened) in preparation for hot water supply again, and when the standby time measured by the standby time measurement timer 33 reaches the valve switching time, the step At 115, the bypass solenoid valve 15 is turned off (closed), and the hot water supply device is put on standby in preparation for re-hot water. When it is determined in step 113 that the bypass solenoid valve 15 is off, that is,
When the set temperature of the water heater is set to a high temperature, the bypass solenoid valve 15 remains in the OFF state and stands by, and the routine proceeds to step 116.

When the flow sensor 9 is turned on in step 116 and hot water is again discharged, the process returns to step 102 to continue the combustion operation of the water heater, and the flow sensor 9 is not turned on in step 116 and the water heater is not turned on. If the hot water is not re-emerged in step 113, return to step 113 and perform the operations from step 113 to step 115 until the hot water is re-emerged in the water heater.
Wait for the hot water heater to return to hot water.

That is, when it is determined in step 114 that the standby time measured by the standby time measuring timer 33 has not elapsed the valve switching time, as shown in FIG. When stopped (time indicated by A in the figure)
The waiting time from when the hot water is re-extracted to the time when the combustion operation is performed again (the time shown in B in the figure) is short, and the time shown in B of the figure when the hot water heater starts the combustion operation by re-hot water is
Since the valve switching time shown in C of the figure has not been reached,
The bypass solenoid valve 15 continues to be in the ON state.

Then, when it is determined in step 114 that the standby time measured by the standby time measuring timer 33 has reached the valve switching time, as shown in FIG. Since the waiting time from the time when hot water supply combustion is stopped to the time when the hot water is discharged again and the combustion operation is started is shown in B of the figure, and the valve switching time shown in C of the figure has elapsed, When the valve switching time shown in C is reached, the bypass solenoid valve 15 is turned off, and in that state, the bypass solenoid valve 15 is turned on again due to the start of the re-leaving hot water and the start of the combustion operation. It is like this. When the bypass solenoid valve 15 is switched from the off state to the on state, even if the bypass solenoid valve 15 is turned on at the same time when the combustion operation of the water heater is started, the detection delay of the on-flow rate and the bypass solenoid valve There will be some delay due to input operation delay.

According to this embodiment, as described above, the combustion operation control unit 40 of the control device 20 controls the combustion operation of the water heater, and the bypass solenoid valve control unit 39 controls the hot water supply from the time when the hot water combustion is stopped. The elapsed time of combustion stop is measured, and from the time when hot water supply combustion is stopped to the time when the valve switching time is reached, the bypass solenoid valve 15 is kept in an open state to wait for the hot water heater to return hot water. When the hot water warmed by is not cold, the hot water and the bypass passage 4
From the hot water supply pipe 11
From 11, no overshoot of hot water comes out, and hot water with a temperature close to the set temperature comes out.

Further, after the elapsed time of hot water supply combustion stop reaches the valve switching time, the bypass solenoid valve 15 is closed and in order to wait for the hot water supply of the hot water supply again, the hot water supply combustion is stopped from the previous time. When a long time has passed and the hot water warmed by the previous combustion operation has cooled, the bypass solenoid valve 15 of the bypass flow passage 4 is in the closed state, and the water from the bypass flow passage 4 is supplied to the hot water supply pipe 11 There is no confluent mixing with the hot water passing through the water, the water passing through the hot water supply pipe 11 is not further cooled by the water from the bypass flow path 4, and hot water having a hot water temperature as close to the set temperature as possible is discharged from the hot water supply pipe 11. The undershoot hot water is prevented from being discharged from the hot water supply pipe 11.

Further, in this embodiment, when the bypass solenoid valve control unit 39 is provided with the high temperature / low temperature setting determination unit 30 and the set temperature input to the temperature setting unit 29 of the remote controller 21 is the high temperature setting. Is a bypass solenoid valve of the bypass passage 4.
15 is in a closed state, and the hot water heated by the heat exchanger 2 does not merge and mix with the water from the bypass flow path 4 even if it passes through the mixing section 19 of the hot water supply pipe 11, As described above, when the combustion operation of the water heater is started, the bypass solenoid valve 15 of the bypass flow passage 4 is always opened so that the water from the bypass flow passage 4 joins and mixes with the hot water from the heat exchanger 2 side. Therefore, it is not necessary to raise the temperature of the hot water heated on the heat exchanger 2 side by the amount of being cooled by the water from the bypass flow path 4, and even when the flow rate is transiently reduced, The risk of boiling can be avoided.

The present invention is not limited to the above-mentioned embodiments, and various embodiments can be adopted. For example, in the above-described embodiment, the valve switching time is set by being obtained by experiments in advance before starting the combustion operation, and the set value is input to the memory unit 34 of the control device 20, but the valve switching time is not necessarily combustion. It is not always necessary to input the value obtained in advance before the operation is started, and as shown in FIG. 4, a step between steps 107 and 109 of the flowchart of FIG.
In addition to the operation of 117, the combustion capacity calculation unit 35 of the control device 20 calculates how much heat was being burned during the previous combustion operation before stopping the combustion operation of the water heater, and the calculation result To the memory section 34, and step 111
Based on the value of the combustion amount of the previous combustion added to the memory unit 34 by the bypass solenoid valve on / off command unit 31, the cross-sectional area difference between the bypass flow path 4 and the hot water supply pipe 11, the outside temperature of the water heater, the incoming water temperature, etc. It is also possible to calculate the valve switching time from, and set the calculated value as the valve switching time.

In this way, the combustion capacity of the water heater at that time is calculated for each combustion operation of the water heater, the amount of heat retained in the heat exchanger 2 is determined, and the valve switching time is variably controlled according to this amount of retained heat. With this configuration, the valve switching time is changed each time depending on how much time elapses after the hot water supply is stopped and the temperature of the hot water sent from the heat exchanger 2 to the hot water supply pipe 11 decreases. Since the hot water is set, hot water having a hot water temperature closer to the set temperature can be discharged when the hot water is again discharged.

Further, in the above embodiment, the high temperature / low temperature setting determination unit 30 of the controller 20 sets the hot water supply temperature to 60 ° C. or 70 ° C.
When it is ℃, it is judged that it is a high temperature setting and the set temperature is 36 to 48
When it was ℃, it was judged to be the low temperature setting, but the high temperature / low temperature setting judgment unit 30 judged that it was always the high temperature setting when the setting temperature was 60 ° C or 70 ° C, and when the setting temperature was 36 to 48 ° C. It is not always determined that the set temperature is the low temperature setting, and the value that the set temperature is determined to be the high temperature setting and the value that is determined to be the low temperature setting are not particularly limited.

Furthermore, the high temperature / low temperature setting determination unit 30 is not necessarily provided in the control device 20, and the control device 20 is configured not to have the high temperature / low temperature setting determination unit 30 and when the set temperature of hot water supply is any value. However, the bypass solenoid valve may be controlled by the bypass solenoid valve control unit 39 as in the above embodiment.

[0044]

EFFECT OF THE INVENTION According to the present invention, the elapsed time from the hot water supply combustion stop in which overshoot hot water comes out and the hot water supply combustion stop from which undershoot hot water comes out at the time of restarting hot water discharge after the stop of hot water supply combustion The time around the boundary of is set as the valve switching time, the elapsed time from the hot water supply combustion stop to the hot water supply combustion stop is measured, and the bypass control valve is opened from the hot water supply combustion stop until the valve switching time is reached. In order to wait for hot water supply again, the bypass control valve is opened when the elapsed time of hot water supply combustion is short enough that the overshoot of hot water does not reach the valve switching time. It remains in the state,
The hot water from the heat exchanger is mixed with the water from the bypass channel, and the hot water near the set temperature is discharged from the tip side of the hot water outlet without overshooting hot water. .

Further, after the elapsed time from the stop of hot water supply combustion to the stop of hot water supply combustion reaches the valve switching time, the bypass control valve is closed to stand by in preparation for hot water discharge again.
When the hot water temperature in the hot water outlet falls after the valve switching time has elapsed, the water from the bypass hot water flow path is not mixed with the hot water in the hot water hot water outlet. Regardless, the water from the bypass flow path is not mixed with the hot water, and the colder hot water is not discharged. You can pour hot water.

Further, when it is judged whether the set temperature of the hot water supply is the high temperature setting or the low temperature setting and the operation method of the bypass control valve is carried out when it is the low temperature setting, the bypass control valve is operated. The operation of is only performed at low temperature setting, and when the set temperature of hot water supply is high temperature, the hot water from the heat exchanger side is not mixed with the water from the bypass flow passage, Since it is not necessary to set the temperature of the hot water heated by the heat exchanger to a high level as much as it is lowered, the risk of boiling inside the heat exchanger is avoided even when the flow rate is transiently reduced. It is possible to supply hot water safely.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing a control mechanism that operates according to an operation method of a bypass control valve while the hot water supply device according to the present invention is on standby for re-hot water discharge.

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-leaving hot water performed by the control mechanism shown in FIG.

FIG. 3 is an explanatory diagram showing a difference in operation of a bypass solenoid valve due to a difference in re-hot water waiting time of the water heater.

FIG. 4 is a flowchart showing another embodiment of the method for operating the bypass control valve during the hot water supply standby for hot water re-emergence.

FIG. 5 is an explanatory diagram of hot water temperature in the hot water supply pipe 11 and the heat exchanger 2 while the hot water supply device is on standby for re-emergence.

FIG. 6 is an explanatory diagram of a bypass mixing type water heater.

[Explanation of symbols]

 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 judgment unit 31 Bypass solenoid valve on / off command unit 33 Standby time measurement timer 39 Bypass solenoid valve control unit

Claims (2)

[Claims] 1. A bypass flow path that bypasses the heat exchanger by connecting the inlet and outlet channels of the heat exchanger of the water heater, and a bypass control valve that opens and closes the flow path is provided in the bypass flow path. In the operation method of the bypass control valve while waiting for re-emergence of the water heater, the overshoot of hot water is generated at the start of re-emergence after the stop of hot water combustion. By setting the time around the boundary of the elapsed time from the combustion stop as the valve switching time, measuring the elapsed time from the hot water supply combustion stop to the hot water supply combustion stop, and bypassing from the hot water supply combustion stop to the valve switching time Open the control valve and wait for re-hot water.After the valve switching time, close the bypass control valve and wait for re-hot water. Bypass control valve operating method. 2. The method according to claim 1, wherein it is judged whether the set temperature of the hot water supply is a high temperature setting or a low temperature setting, and when it is the low temperature setting.
A method for operating the bypass control valve during standby for re-emergence of a water heater, which performs the method for operating the bypass control valve as described.