JPH03274351A - Flow controller of hot-water supply apparatus - Google Patents

Abstract

PURPOSE:To stabilize the supply flow rate and temperature of hot-water when the hot-water flow rate is restricted, by a method wherein a flow controller performs controls corresponding to a target flow rate until a specified time period elapses after hot-water supply is started, and controls do not take place after the specified time period. CONSTITUTION:A water circuit controller performs hot-water supply control or hot-water filling control in a specified sequence corresponding to an instruction from a remote controller. At this time, the water circuit controller calculates a target flow rate as a maximum flow rate at which water can be heated up to the set temperature by a hot-water supply burner 4 operated at the maximum combustion rate so that a hot water supply rate as much as possible can be achieved and a fast hot-water filling can be carried out, and regulates a hot-water flow servo valve 15 so that the flow rate detected by a flow sensor 31 reaches the target flow rate. The flow control by the servo valve 15 according to the target flow rate continues until a specified time period passes after hot-water supply is started, and is not carried out after the specified time period is elapsed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow rate control device for a water heater that controls a flow rate control device in accordance with the temperature of water flowing into a water circuit including a heat exchanger.

[Prior Art] In water heaters, the maximum heating capacity that can be obtained by gas burners, etc. for heating the water passing through the heat exchanger is limited, so the water circuit including the heat exchanger is equipped with a valve, for example, by a geared motor. Equipped with a flow control device that drives the body to adjust the flow rate, and if the target temperature is not achieved, the flow rate of water passing through the heat exchanger is restricted to ensure that the temperature of the water flowing out reaches the target temperature. That's what I do.

In addition to simply limiting the flow rate, in order to obtain as much flow rate as possible for the target temperature,
The maximum flow rate corresponding to the maximum heating capacity of the gas burner, etc. is calculated in advance from the target temperature and the temperature of the water supplied to the heat exchanger I, and the flow rate adjustment device is controlled and calculated so that the maximum flow force is biased. An operation to increase the flow rate is also performed so that the flow rate is obtained.

[Problems to be Solved by the Invention] By the way, bathrooms and sinks in ordinary homes are sometimes equipped with a mixing faucet that mixes hot water from a water heater with water directly supplied from the water supply system. In addition, some mixer faucets are equipped with a thermovalve that can automatically adjust the mixing ratio of hot water from a water heater and water from a tap water supply, etc., to match the temperature desired by the user.

When supplying or filling hot water using a mixer faucet with a thermo valve, the mixer faucet adjusts the amount of hot water completely independent of the water heater's control status, so the water heater does not calculate the amount of hot water. Even if the flow rate is adjusted to obtain the maximum flow rate, the hot water flow rate will change depending on the temperature of hot water supplied to the mixer faucet.

As a result, on the water heater side, the opening degree of the flow rate adjustment device that has been adjusted by -length is changed again, and the flow rate is changed to the optimum flow rate.On the other hand, on the mixing faucet side, the flow rate adjustment device When the flow rate is readjusted by the hot water flow rate, the hot water flow rate is further adjusted, and if these steps are repeated, the flow rate becomes unstable and the hot water temperature changes as the flow rate fluctuates. However, there is a problem in that the flow rate and temperature of hot water are not stable forever, causing hunting.

Similarly, even when hot water is supplied using a regular faucet, if the water supply flow rate is restricted by the user, the flow rate will be adjusted by the flow control device, which will cause the flow rate to become unstable and cause the hot water temperature to rise. The problem is that it becomes unstable.

In the present invention, a target flow rate is calculated in advance so that as much hot water supply flow rate as possible can be obtained in accordance with the set temperature.
The purpose of this invention is to stabilize the flow rate and outlet temperature in a water heater flow rate control device in which a flow rate regulating means is controlled so as to obtain the flow rate when the hot water supply flow rate is restricted by a user or the like.

[Means for Solving the Problems] The present invention provides temperature setting means for setting the temperature of hot water flowing out from a water circuit including a heat exchanger heated by a heating means, and detecting the temperature of water flowing into the water circuit. and a flow rate detection means for detecting the flow rate passing through the water circuit, the water circuit is determined based on the maximum heating capacity of the heating means, the set temperature of the temperature setting means, and the detected temperature of the water input temperature detection means. In a water heater flow control device that determines a target flow rate of the water supply circuit and controls a flow rate adjustment means for adjusting the flow rate of the water circuit according to the target flow rate, the flow rate adjustment means is controlled according to the target flow rate. The technical means is to continue the process until a predetermined time has elapsed after the start, and not to perform the process after the predetermined time has elapsed.

[Function] According to the present invention, when hot water supply is started, the maximum flow rate according to the heating capacity of the heating means is calculated according to the set temperature and the water supply temperature, and the flow rate adjustment means is controlled so that the flow rate is obtained. .

The flow rate adjustment control performed by the flow rate adjustment means based on this target flow rate is performed until a predetermined time has elapsed after the start of hot water supply, and is not performed after the elapse of the predetermined time.

Therefore, when the faucet is opened wide to require as much flow as possible, or when the valve for filling hot water is opened, the flow rate is adjusted during this predetermined time. This results in heating at as high a flow rate as possible.

・On the other hand, if the user restricts the flow rate with a faucet or a thermo valve, the flow rate adjustment means will operate to increase the flow rate during a predetermined period of time. Although the flow rate and hot water temperature are unstable, this does not have a large effect because the hot water temperature is difficult to stabilize at the initial stage of hot water supply into the shell.

Furthermore, after a predetermined period of time has elapsed, the flow rate adjustment means will no longer adjust the flow rate according to the target flow rate, so if the flow rate is restricted as necessary, the flow rate will be stabilized, and as the flow rate is stabilized, the outlet temperature will also be stabilized. do.

[Effects of the Invention] According to the present invention, when a large flow rate is required, the flow rate adjustment means is controlled according to the target flow rate during a predetermined period of time after hot water supply starts, and the flow rate adjustment means is controlled according to the target flow rate to adjust the flow rate to the set temperature. Hot water can be supplied at a limited flow rate, and even after a predetermined period of time has elapsed, hot water supply can be continued at that flow rate.

In addition, after the predetermined time has elapsed, the flow rate adjustment means is not controlled according to the target flow rate, so the flow rate adjustment device does not adjust to the target flow rate, contrary to the operation of the faucet or the thermo valve.
Since there is no need to change Xjl, the flow rate becomes stable.

Therefore, the hot water temperature is stabilized.

[Example] Next, the present invention will be explained based on examples.

The gas hot water bath system 1 shown in FIG. 2 is a composite hot water system equipped with functions such as an automatic hot water filling function and a reheating function. Heating several hot water ports A and bathtub B
A main heater 2 for supplying hot water to the bathtub B, a bath heater 3 for circulating and heating the hot water in the bathtub B, and each of these heaters 2゜3, hot water inlet A, and bathtub B are connected to It consists of several pipes forming a circuit.

The water pipe 10 includes a flow rate sensor 31 that detects the rotation of an impeller that rotates in accordance with the flow rate with a Hall element to detect the flow rate of passing water and generates a pulse signal, and a flow rate sensor 31 that detects the temperature of the supplied water Tin. A water supply temperature thermistor 32 is provided, and the water pipe 10 branches downstream of these, one being connected to the main heat exchanger 11 of the main heater 2, and the other being connected to the main heat exchanger 1.
1, and the bypass pipe 12 includes a bypass solenoid valve 1 that is opened as necessary.
3 are provided.

Output pipe 1 where main heat exchanger 11 and bypass pipe 12 merge
4 includes an electric hot water amount servo 15 whose valve body is driven by a geared motor in order to limit the amount of hot water flowing out;
A hot water temperature thermistor 33 for detecting hot water temperature TOLlt is provided, and the hot water pipe 14 branches downstream of these, one being a hot water supply pipe 16 to each hot water supply port A, and the other being a connecting pipe to the bath heater 3. 17.

The connecting pipe 17 includes a water flow sensor 34 for detecting the amount of hot water filled, a vacuum breaker 35 for opening the hot water supply circuit to the atmosphere to prevent hot water from flowing back into the bathtub B in the event of a water outage, etc., and a vacuum breaker 35 that opens the hot water supply circuit to the atmosphere when filling hot water. A hot water filling valve 18 consisting of a ball valve that can be rotated, and two check valves 19 that prevent hot water from flowing back into the bathtub B.
．． 19a is provided.

The connecting pipe 17 branches into two upstream of the bath heater 3,
One is a hot water filling pipe 20 to the bathtub B and is connected to the bathtub B, and the other is connected to one side of the bath heat exchanger 21 of the bath heater 3.

The other side of the bath heat exchanger 2] is a circulation pipe 22 connected to the bathtub B in the same way as the hot water filling pipe 20 in order to circulate hot water from the bathtub B. A water level sensor 36, a pump 23, an on-off valve 24, a water flow switch 37, and a bath thermistor 38 are provided in order from bathtub B@.

The water level sensor 36 is a semiconductor diffusion resistance type pressure sensor that utilizes a piezoresistance effect, and is built into a diaphragm chamber in which one side communicates with the circulation piping 22 and the other side is open to the atmosphere. It is possible to detect the resistance value.

When energized, the pump 23 rotates at a constant rotation, pumps up the hot water in the bathtub B from the circulation pipe 22, sends it to the bath heat exchanger 21, and circulates it to the bathtub B again from the hot water filling pipe 20.

The on-off valve 24 is a rotary valve whose pipe-shaped valve body through which hot water can pass in either direction I\ is driven by a servo motor. In order to form a bath circulation path and to detect the water level by the water level sensor 36, the bong 12
3, the circulation piping 22 is closed.

Moreover, when the main heater 2 is filling with hot water, it is in an open state, so that not only the hot water filling pipe 20 but also the circulation pipe 22 can be filled with hot water.

The water flow switch 37 is used to detect whether or not hot water is passing through the circulation piping 22 when the pump 23 is activated. The bath thermistor 38 that does not detect the pump 2
3, the temperature of the hot water in bathtub B is detected.

The main heater 2 heats the main heat exchanger 11 by burning water with the hot water burner 4 when water passes through the wood pipe 10 .

The fuel pipe 40 to the hot water supply burner 4 is provided with a solenoid valve 40a for stopping all fuel supply, and downstream thereof is a governor proportional valve 41 that adjusts the amount of fuel supplied according to the required heating amount. , electromagnetic valves 42 and 43 are provided to control the number of burners to be used among all the burners of the hot water supply burner 4, and the hot water supply burner 4 controls the fuel gas regulated by these valves.
Combustion is performed by mixing with combustion air supplied by a hot water blower 44 9 The bath heater 3 includes a bath fuel pipe 4 branched from a fuel pipe 40
The fuel gas supplied from the bath burner 5 is combusted by the combustion air supplied by the bath blower 46.
The bath heat exchanger 21 is heated.

The bath fuel pipe 45 is equipped with a governor 47 for keeping the supply gas pressure constant and a bath solenoid valve 48 for controlling fuel supply, and the bath burner 5 is equipped with a solenoid valve 49 for controlling the number of burners used. It is being

The gas hot water bath system I having the above configuration is controlled by a control device 50.

The control device 50 is mainly composed of a microcomputer, and has a functional tank or, as shown in FIG. , a water circuit control section 53 that controls the water circuit, and a remote control 6 that sets the hot water supply temperature, hot water filling temperature, and hot water filling amount, and also instructs the operating state.
0.

The remote controller 60 has several operation switches for instructing hot water supply or several types of hot water filling, and setting switches for setting the set temperature Tset, the amount of hot water filling, and the time related to hot water filling for each operation, and other settings. There is a display section to display various settings, current time, etc., and a buzzer that goes off when the water is filled.

The hot water supply control unit 51 is provided in the hot water supply blower 44, the solenoid valve 40a, the solenoid valves 42 and 43, and the hot water burner 4 according to water flow information based on the flow rate sensor 31 when hot water is being supplied or filled. The ignition electrode 4a is controlled in a predetermined sequence to control the ignition of the hot water supply burner 4, and the temperatures detected by the supply water temperature thermistor 32 and the hot water temperature thermistor 33, the flow rate detected by the flow rate sensor 31, and the set temperature by the remote control 60 are controlled. +'set, calculates the required heating amount by the hot water supply burner 4, controls the hot water supply blower 44 based on this required heating amount, detects the rotation speed of the hot water supply blower 1144, and controls the governor proportional valve 41, The solenoid valve 42 is controlled to control the combustion amount of the hot water supply burner 4.

In addition, fire extinguishing control is performed based on water flow stop information from the flow rate sensor 31.

During combustion, the flame is detected by the flame rod 4b provided in the hot water burner 4, and in the event of a misfire, each solenoid valve such as the main solenoid valve 40a is closed to stop the fuel supply.
Stop combustion.

In the case of fully automatic operation, when the bath temperature is detected by the bath thermistor 38 at predetermined intervals after filling the water, and the bath temperature is lower than the set temperature TSet, the bath control unit 52 sets a predetermined value to Bath blower 46 in sequence,
The bath solenoid valve 48 and the ignition electrode 5a provided in the bath burner 5 are controlled to control the ignition of the bath burner 5, and the water flow in the bath circulation path is detected by the water flow switch 37 as the bong 123 is activated. The bath is heated until the temperature of the water circulating in the bath circulation path rises to the set temperature TSet.

The combustion amount of the bath burner 5 during combustion is controlled by a solenoid valve 49 according to the temperature difference between the detected temperature and the set temperature 1'Set.
determined by

Further, the flame of the bath burner 5 is detected by a flame rod 5b provided in the bath burner 5, and if a misfire occurs, fuel supply is stopped to stop combustion.

The water circuit control unit 53 performs hot water supply control or hot water filling control in a predetermined sequence according to instructions from the remote controller 60, and at this time, the hot water supply burner 4 performs heating at the maximum combustion rate to increase the amount of hot water supply as much as possible. In order to quickly fill the hot water, the maximum heating amount of the hot water burner 4, the set temperature TSet by the remote controller 60, and the water supply temperature T at the water pipe 10 detected by the water supply temperature thermistor 32 are set.
Based on in, a target flow rate F0 as the maximum flow rate that can be heated to the set temperature 1'' is calculated, and the hot water flow servo 15 is adjusted so that the flow rate F detected by the flow rate sensor 31 becomes the target flow rate F. .

In this case, in order to reduce fluctuations in the hot water temperature 'rout, the water supply temperature thermistor 3
2, the detected feed water temperature Tin is memorized, and the target flow rate F is determined based on the memorized feed water temperature Tin and the set temperature T Set.
. is calculated, and thereafter, the target flow rate F0 is not changed even if the feed water temperature Tn changes.

Also, the calculated target flow rate F. Depending on the water flow servo 15
When controlling the target flow rate F. If a flow rate reduction operation is performed after a flow rate greater than or equal to the target flow rate is detected, the flow rate adjustment operation is restricted so that a flow rate increase operation is not performed even if a flow rate F smaller than the target flow rate F0 is detected thereafter. are doing.

Note that this restriction on the flow rate adjustment operation is performed only while the hot water supply or hot water filling continues; - once the hot water supply or hot water filling is finished, the flow rate adjustment operation is performed again, and this If necessary, an operation to increase the flow rate is performed.

Furthermore, even if hot water supply or filling is continued, if the set temperature Tspt is changed using the remote controller 60 and the target flow tFo is recalculated,
New target flow rate F. The flow rate is adjusted accordingly.

Note that whether or not there is a change in the set temperature 'I'set is monitored only until a predetermined time t, for example 30 seconds, has elapsed since the start of hot water supply or filling. After this period has elapsed, no flow rate adjustment control is performed using the target flow rate F0.

After the predetermined time t has elapsed, flow rate adjustment control is performed based on the hot water outlet temperature TOut detected by the hot water outlet temperature thermistor 33, and the flow rate is reduced only when the hot water outlet temperature 'x''out has not reached the set temperature Tset. Only the operation is performed, and no flow rate increase operation is performed.

As a result, for example, if a mixing tank equipped with a thermo-valve to which water is directly supplied from the water supply etc. is installed as hot-water inlet A, the amount of hot water supplied may change due to the temperature adjustment by the thermo-valve. Even if the flow rate changes as a result, the flow rate adjustment control on the hot water flow servo 15 side will not be performed accordingly, so the flow rate will remain constant due to the corresponding action between the thermo valve and the hot water flow servo 15. There is no instability, there is no variation in the hot water outlet temperature Tout due to changes in the flow rate, and only the heating amount of the hot water supply burner 4 is controlled, so a stable hot water outlet temperature "'t'out" can be obtained.

Hereinafter, the flow of control of the water circuit control section 53 at the initial stage of starting hot water filling will be explained based on FIG. 1, taking the case of hot water filling control as an example.

When the hot water filling valve 18 is opened in response to an instruction from the remote controller 60 and hot water filling starts, a target flow rate F0 is calculated according to the set temperature Tset and the water supply temperature Tin (step 1).
), the calculated target flow rate F. The hot water flow servo 15 is driven according to the target flow rate F.

Flow rate adjustment control is performed to obtain (step 2)
).

After this, if there is a change in the set temperature TSet (YES in step 3), the process moves to step 1, the target flow rate F0 is calculated again, and the flow rate adjustment control is performed according to the new target flow rate F0.

Recalculation of the target flow rate F0 in response to a change in the set temperature TSet is performed only during a period from the start of filling with hot water until a predetermined time t has elapsed (No in step 4).

The set temperature TSet is not changed (N in step 3).
O>, if a predetermined time t has elapsed since the start of filling the hot water (YES in step 4), from then on, the set temperature]'set and the hot water outlet temperature 'rout are compared, and the hot water outlet temperature 'rout is set. Only if the temperature T set is not reached (No in Stella 15), a flow rate reduction operation is performed (step 6) to ensure that the outlet temperature "t'out" can be heated up to the set temperature T set.

On the other hand, if the hot water temperature Tout has reached the set temperature TSet (YES in step 5), the flow rate will not be increased and the flow rate will be maintained even if the hot water supply burner 4 has sufficient heating capacity. do.

As a result, the flow rate of hot water tapped can be stabilized, and fluctuations in hot water temperature due to changes in flow rate can be eliminated.

After that, until the amount of hot water reaches the set amount (step 7)
(NO in step 5), set temperature TSet in step 5
and the outlet temperature TOut, and only the flow rate reduction operation (step 6) is performed accordingly.

When the amount of hot water reaches the set amount, press YES in step 7.
S) After filling the hot water, move on to heat retention control (Step 8)
.

Next, regarding the flow rate adjustment control in step 2, the fourth
This will be explained with reference to the diagram.

Here, the flow rate F detected by the flow rate sensor 31 and the calculated target flow rate F. If the flow rate F is the target flow rate F0 (r-'' in step 11), the process moves to step 3 without driving the hot water amount servo 15 to adjust the flow rate.

Step 11 if the flow rate F is greater than the target flow rate F0
(">"), the flow rate reduction operation is performed by the hot water amount servo 15 (step 12).

In the hot water flow servo 15, the flow rate detected by the flow rate sensor 31 is the target flow rate F. (Step 13)
(NO), the flow rate F detected by the flow rate sensor 31 is the target flow rate F. If the value is below (YES in step 13), the flow rate adjustment control is finished and the process moves to step 3.

On the other hand, if the flow rate F is smaller than the target flow rate F0 ('<J in step 11), the flow rate is increased by the hot water flow servo 15 (step 14), and then in step 1
1 and repeat the determination.

As a result, the hot water amount servo 15 is driven to open so that the flow rate F is smaller than the target flow rate F0.

In addition, in the comparison between the flow rate F and the target flow rate Fo in step 11, in order to ensure the stability of the operation of the hot water flow servo 15, a certain width is given to the target W and the flow rate F0.
Moreover, in the gap for driving the hot water amount servo 15, the hot water amount servo 1
In order to quickly drive the water flow rate F0 to the target flow rate F0 and to obtain sufficient driving torque for the water pressure, the voltage applied to the geared motor of the hot water flow servo 15 is kept constant, and the flow rate detected by the flow rate sensor 31 is maintained constant. F is the target flow rate. A voltage is continuously applied until the flow rate F is within a predetermined range, and once it is within the predetermined range, pulses of the same voltage are applied at intervals to gradually change the target flow rate F0.

However, when increasing the flow rate, due to the influence of the pressure of hot water passing through the hot water flow servo 15, etc.
. Even if the drive of the hot water flow servo 15 is stopped when the flow rate is reached, the flow rate F may not always be able to reach the target flow rate F0. However, in this embodiment, when the flow rate increase operation is performed, Step 14), and then proceed to step 11, so the flow rate reduction operation in step 12 can be performed after the flow rate increase operation, so there is no possibility that the outlet temperature "i" out does not reach the set temperature Tset due to excessive flow rate. .

Conversely, once the flow rate is reduced to prevent the flow rate F from becoming excessive, the flow rate F is stabilized because no flow rate increase operation is performed even if the heating power of the hot water supply burner 4 is sufficient. As a result, changes in the flow rate will not affect the outlet hot water temperature and cause the hot water temperature to fluctuate.

The water circuit control unit 53 controls the bypass solenoid valve 13 when a large flow rate of hot water is required for both hot water supply and filling, and when the set temperature "l" set is relatively low and the load on the hot water supply burner 4 is small. A large amount of hot water is supplied in a short period of time by opening the unheated water to guide unheated water to the hot water outlet pipe 14 and burning the hot water with the largest possible combustion amount by utilizing the heating ability of the hot water supply burner 4.

In automatic hot water filling control, when filling hot water for the first time after completing installation work, a predetermined filling water amount calculation control is performed to calculate the hot water supply amount Wa corresponding to the set water level for each bathtub. and memorize it.

In addition, when the bathtub is installed for the second time or later when the water filling amount calculation control has been completed and the hot water supply amount Wa corresponding to the bathtub is memorized, the instruction to fill the hot water is given from the remote control. At this time, the hot water filling valve 18 is opened to start filling the bathtub B with hot water, and the water filling amount W is measured by the water amount sensor 34 until the hot water supply amount Wa reaches a predetermined amount corresponding to the set water level.
After the predetermined hot water supply amount Wa has been reached, the water level sensor 36 detects the actual water level to determine whether it has reached the set water level, and continues filling the water until the set water level is reached. When the water level reaches the set level, the hot water filling valve 18 is closed.

In this hot water filling control, especially when there is sufficient hot water supply capacity, the hot water filling valve 18 is used to speed up the hot water filling time.
The on-off valve 24 is opened and closed in a predetermined sequence to prevent water hammer from being applied to the water level sensor 36, and the on-off valve 24 is opened to fill hot water from the circulation piping 22 as well.

As described above, in the gas hot water bath system 1 of the present embodiment, when starting hot water supply or filling, if the flow rate is limited by first performing a flow rate reduction operation, then the set temperature "i" set is Since the flow rate increase operation is not performed except when the water supply temperature Tin is changed, the flow rate does not become unstable due to fluctuations in the water supply temperature Tin.

In addition, by performing a flow rate reduction operation, the flow rate is restricted, so that the outlet hot water temperature TOut is reliably set to the set temperature T set.
It can be done.

Further, even if the water supply temperature Tin changes, the flow rate is not adjusted accordingly, so the hot water temperature Tout can be stabilized.

On the other hand, when the set temperature T set is changed, the flow rate is adjusted accordingly, so that the outlet temperature Tout can be set to the set temperature T Set.

In addition, even if the required hot water temperature cannot be obtained due to insufficient heating power due to a change in the water supply temperature Tin, the flow rate can be adjusted by changing the set temperature, so the required temperature can be achieved. be able to.

Furthermore, after a certain period of time has elapsed after the start of hot water supply or filling, no flow adjustment operation is performed according to the target flow rate. Even when the amount of hot water is adjusted, the flow rate does not become unstable due to the interaction between the thermo valve and the hot water amount servo 15.

As a result, the hot water temperature can be stabilized.

In the above embodiment, in the main heater, the main heat exchanger 11
Although a bypass pipe 12 is provided to detour the pipe 12, it may be provided without the bypass pipe 12.

Further, in the above embodiment, the water pipe 1 upstream of the main heat exchanger 11
0 is shown as having a water supply temperature thermistor 32, but the water supply temperature may be estimated using a hot water temperature thermistor 33.

In the above embodiment, a gas hot water bath system was shown, but
It can also be applied to burners using other fuels such as petroleum or water heaters using electric heat.

[Brief explanation of drawings]

FIG. 1 is a flowchart for explaining the water circuit control operation by the control device in a gas hot water bath system showing an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the gas hot water bath system,
FIG. 3 is a functional block diagram of the control device of this embodiment, and FIG. 4 is a flowchart for explaining flow rate adjustment control by the control device of this embodiment. In the figure, 4... Hot water burner (heating means), 10... Main pipe (water circuit), 11... Main heat exchanger (heat exchanger), 14
... Hot water pipe (water outlet 1i) -15... Hot water flow servo (flow rate adjustment means), 31... Flow rate sensor (flow rate detection -1''
stage), 32... Water supply temperature thermistor (inlet water temperature detection means)
, 50...control device (water heater flow rate control bag ff), 6
0...Remote control (temperature setting means).

Claims (1)

[Scope of Claims] 1) Temperature setting means for setting the temperature of hot water flowing out from a water circuit including a heat exchanger heated by a heating means, and incoming water temperature detection means for detecting the temperature of water flowing into the water circuit. ,
A flow rate detection means for detecting the flow rate passing through the water circuit is provided, and a target flow rate of the water circuit is determined from the maximum heating capacity of the heating means, the set temperature of the temperature setting means, and the detected temperature of the inlet water temperature detection means. , a flow rate control device for a water heater that controls a flow rate adjusting means for adjusting the flow rate of the water circuit according to the target flow rate, wherein the control of the flow rate adjusting means according to the target flow rate is performed for a predetermined period of time after the start of hot water supply. A flow rate control device for a water heater, characterized in that the flow rate control device controls the flow rate until the predetermined time period has elapsed, and does not control the flow rate after the predetermined time period has elapsed.