JPH1123061A - Hot water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform rapid supply of desired temperature hot water during supply of hot water by respectively specifying a set time in which post purge during heat insulation combustion control and hot water supply combustion control is executed and a set time in which post purge during switching command is executed in a device to effect heat insulation and heating of hot water in the device. SOLUTION: A control part H is provided with hot water supply combustion control means 100 to execute hot water supply combustion control, a heat insulation combustion control means 101 to execute heat insulation combustion control during waiting for hot water supply, a heat insulation control diversion means 102, and a command means 104 to effect switching command of a time of hot purge. During hot water supply combustion control and heat insulation combustion control, a set time in which host purge is executed is set to a short heat insulation state maintaining time to an extent that, during heat insulation combustion control after a stop of combustion of a burner 3, a heat-exchanger is not cooled by a post purge. Further, a set time in which post purge is executed during a switching command is set to a long operation stable time long enough to allow stabilization of a drive state of a fan 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for heating water for heating supplied water to discharge hot water, a burner for heating the heat exchanger, and ventilation of combustion air to the burner. A fan, and control means for controlling the operation of the burner and the fan are provided, and the control means starts combustion of the burner as water flow to the heat exchanger is started, It is configured to execute hot water supply combustion control for stopping the combustion of the burner as the water flow is stopped, and to perform ventilation by the fan in accordance with the combustion of the burner. When stopped,
The present invention relates to a hot water supply device configured to continue ventilation by a fan for a set time and then execute post-purge for stopping ventilation by the fan.

[0002]

2. Description of the Related Art Conventionally, in the above hot water supply apparatus, the hot water supply combustion control is always executed, and after the hot water supply is stopped and the flow of water to the heat exchanger is stopped, the hot water supply is started again. Until this was done, the burner was kept in a combustion stopped state.

[0003] The set time for executing post-purge after the burner is stopped has been set to a relatively long time (for example, about several minutes). Executing the post-purge for such a long time is a process for surely discharging the combustion exhaust gas and unburned components to the outside, and using this post-purge to maintain a proper ventilation state by the fan. Is to execute. That is,
When the driving state of the fan is stabilized when executing the post-purge, based on the operating state of the fan (for example, the correlation between the rotation speed and the driving power), the ventilation state of the ventilation path by the fan, for example, dust In order to avoid the incomplete combustion caused by the insufficient ventilation volume, determine the path clogging etc. due to the air flow, etc., correct the operating state (target rotation speed, etc.) of the fan to an appropriate state, and maintain the ventilation state properly. Control operation and the like.

[0004] In the hot water supply combustion control accompanying the flow of water to the heat exchanger, the outlet water temperature is set to a set temperature, and
The combustion amount of the burner and the air flow rate of the fan are controlled to appropriate values so that the burner does not enter an incomplete combustion state.

[0005]

In the above-mentioned conventional construction, if the elapsed time from the stop of tapping to the start of tapping again becomes long, the temperature of the heat exchanger heated by the burner decreases. However, the hot water in the heat exchanger will drop to a temperature close to the temperature of the supplied water, and when re-watering is started, such low-temperature hot water is discharged and the temperature is lowered. There is a disadvantage that it takes time until the heat exchanger is heated by the burner and the hot water temperature rises to a desired temperature.

[0006] As a method for solving such disadvantages, a circulation path is formed by connecting a hot water path and a water inlet path, and a circulation pump is provided in the circulation path. When the combustion of the burner is stopped, the burner is intermittently burned by operating the circulation pump intermittently to circulate hot water through the circulation path and to pass through the heat exchanger. Is heated, and the temperature of the hot water in the circulation path is maintained at the set hot water temperature by using the heating operation of the burner. There was something that could be hot water.

However, the above configuration requires special piping, a circulation pump, and the like for forming the circulation path, which increases the number of parts, complicates the configuration and increases the cost. There was still room for improvement.

Therefore, in order to eliminate such disadvantage, in a state where the flow of water to the heat exchanger is stopped, the flow of heat inside the water heater is controlled by a heating operation by a burner in a control state similar to the hot water supply combustion control. It is conceivable to heat and maintain the hot and cold water in the water channel, but in such a configuration, there is no need to provide a circulation pump or a special circulation pipe, and the configuration becomes simple. It is conceivable that the post-purge for a relatively long period of time causes the heat exchanger to radiate heat and the heated and heated water to radiate heat, thereby causing a problem that low-temperature hot water is discharged.

The present invention has been made in view of such a point, and an object of the present invention is to heat and heat the hot water in the apparatus, without complicating the configuration and controlling the ventilation state of the fan. To provide a hot water supply device that can supply hot water at a desired temperature or a temperature close to it as quickly as possible at the start of hot water supply while enabling processing for properly maintaining or discharging combustion exhaust gas to the outside, etc. is there.

[0010]

According to the first aspect of the present invention, the control means satisfies a condition for starting warm combustion in a state where the flow of water to the heat exchanger is stopped. To start the combustion of the burner, and to perform the warming combustion control for stopping the burning of the burner when the set condition for stopping the warming combustion is satisfied, and post-purge in each of the hot water supply combustion control and the warming combustion control. Is set so as to be short enough to keep the heat exchanger from being cooled by the post-purge after the burner combustion is stopped in the warming combustion control. Then, based on the switching command by the command means,
The post-purge execution time is configured to be set to a long operation stabilization time sufficient for stabilizing the driving state of the fan, instead of the heat-retention state maintenance time.

That is, when the tapping of the hot water is stopped and the flow of water to the heat exchanger is stopped, the set conditions for starting the warming combustion,
For example, when the temperature of the hot water in the hot water path inside the apparatus such as the inside of the heat exchanger or the hot water path decreases, or when the time of about the temperature of the heat exchanger decreases after the hot water is stopped, etc. When a condition that can be considered that the temperature of the hot and cold water in the hot water passage inside the device is satisfied, the combustion of the burner is started and the hot water inside the device is started regardless of whether or not water is passed through the heat exchanger. Heat the hot water in the road. And
Setting conditions for stopping the insulated combustion, for example, when the hot water temperature in the hot water passage inside the device rises to the set temperature, or when the set time has elapsed since the start of burner combustion, etc. Burner combustion is stopped when a condition is met such that the temperature of the hot water can be considered to have risen to or near the desired temperature.

Therefore, as compared with the conventional configuration in which burner combustion is started only when water is passed through the heat exchanger, no special member for passing water through the heat exchanger is required, and the configuration is complicated. Without causing the hot water in the hot water path inside the apparatus to be maintained at a desired temperature or a temperature close to the desired temperature as much as possible. It is possible to do.

In addition, the post-purge execution time in each of the hot-water supply combustion control and the heat-retention combustion control is such that the post-purge stops the burner combustion during the heat-retention combustion control, and the heat retention state is short enough that the heat exchanger is not cooled by the post-purge. Since the time is set, the heat exchanger is radiated and cooled due to the ventilation by the fan, and it is suppressed that the hot water in the heat exchanger to be kept warm is cooled unnecessarily. Can be properly maintained.

If the post-purge is always performed only for a short time as described above, it may be considered that the exhaust gas such as the combustion exhaust gas and unburned components of the burner may not be sufficiently discharged to the outside. In order to avoid incomplete combustion due to insufficient ventilation due to a blocked ventilation path, etc., the operation state of the fan is corrected to an appropriate state and the control operation for maintaining the ventilation state properly is performed. However, based on the switching command by the command means, the post-purge execution time is set to a long operation stabilization time sufficient to stabilize the driving state of the fan, instead of the heat retention state maintenance time. Therefore, by performing post-purge for a sufficiently long time in such a switched state, it is possible to reliably discharge combustion exhaust gas and the like to the outside, and It from becoming possible to perform the control operation or the like for to maintain proper ventilation state as.

The instructing means is configured to automatically execute the hot water supply combustion control every time the number of times of execution reaches the set value.
A configuration that automatically performs each time a predetermined time elapses, or
Various configurations can be considered, such as a configuration in which a command is given by an artificial operation at appropriate intervals.

According to a second aspect of the present invention, in the first aspect, a rotation speed detecting means for detecting a rotation speed of the fan and a drive power for the fan are adjusted so that the rotation speed becomes the target rotation speed. A fan driving unit, wherein the control unit drives the fan to set the post-purge set rotation speed as the target rotation speed when performing the long-time post-purge with the operation stabilization time set. Means for controlling the operation of the means, and for correcting the target number of revolutions based on a deviation between the current driving power and the driving power in the long-time post-purge executed earlier than that time. It is configured to execute number correction control.

In the case where the driving power is adjusted so that the fan rotation speed becomes a predetermined rotation speed in the ventilation by the fan,
When the ventilation resistance is large due to a blockage in the ventilation path, etc., the driving power becomes smaller than the case where the ventilation resistance is small. The state of the ventilation path is detected in comparison with the value, and the operating state of the fan is corrected in accordance with the state of the ventilation path.

In other words, the control means controls the operation of the fan drive means based on the detection information of the rotation speed detection means so as to reach the post-purge set rotation speed when the post-purge is executed for a long time. At this time, since the driving state of the fan is stabilized by driving for a long time, the set number of rotations for post-purging is surely achieved. Therefore, based on the deviation between the driving power at that time and the driving power in the long-time post-purge executed before that time, when ventilating the burner combustion in the hot water supply combustion control and the warming combustion control, Is corrected to an appropriate value.

According to a third aspect of the present invention, in the first or second aspect, the instructing means automatically instructs a switching instruction each time the number of times of executing the hot water supply combustion control reaches the set number. Is configured.

Therefore, when the hot water supply combustion control reaches the set number of times, the post-purge is automatically executed for a long time. Can be commanded at an appropriate timing.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the input path and the tapping path are respectively connected to the heat exchanger, and the hot water in the tapping path or the heat exchanger is connected to the heat exchanger. Hot water temperature detecting means for detecting the temperature is provided, and the control means is configured to, when the detected value of the hot water temperature detecting means is equal to or less than a set lower limit value, determine that the set condition for the start of warming combustion is satisfied. ing.

Therefore, the temperature of the hot water flowing out at the next hot tap is directly detected, and the warming combustion is started based on the detected temperature, so that the temperature of the hot water supplied at the time of hot tapping becomes lower than the set lower limit. Can be reliably prevented.

According to a fifth aspect of the present invention, in the fourth aspect, the control means responds to the changed target hot water supply temperature as the target hot water temperature is changed in the warming combustion control. It is configured to change the set lower limit value.

Accordingly, the set lower limit value for starting the warming combustion is changed in accordance with the change of the target temperature for hot water supply, so that hot water having a temperature corresponding to the target temperature can always be supplied at the time of tapping. It becomes easy to use.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the control means may include, in the warming combustion control, when a set time for the warming combustion elapses from the start of the burner combustion. It is configured to determine that the set condition for stopping the warming combustion is satisfied.

That is, when the combustion of the burner is started in the insulated combustion control, the hot and cold water in the heat exchanger is heated in a state where the water is not passed through the heat exchanger, and the combustion is continued for a long time. Then, since the temperature of the hot water exceeds the desired temperature for tapping and rises too high to a high temperature, the combustion of the burner is stopped after the set time has elapsed.

As a result, at the start of hot water supply, the hot water temperature is suppressed from becoming high, and hot water having a temperature at or near the set temperature is supplied as quickly as possible.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, when the detected value of the hot water temperature detecting means is equal to or more than the set upper limit value, the control means sets the temperature for stopping the insulated combustion. It is configured to determine that the condition is satisfied.

As a result, at the start of hot water supply, it is possible to prevent the hot water temperature from becoming too high due to an excessive rise in hot water temperature due to the heat retaining combustion operation, and to supply hot water at or near the set temperature. Become.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a hot water supply apparatus according to the present invention will be described. As shown in FIG. 1, the hot water supply apparatus includes a hot water supply unit K for heating supplied water and supplying hot water to a hot water tap (not shown), a control unit H as control means for controlling the operation of the hot water supply unit K, A remote control operation unit R for instructing the H to input operation information is provided.

The hot water supply section K has a heat exchanger 2 for heating water, a gas combustion type burner 3 for heating the heat exchanger 2, and a combustion air flowing through the burner 3 in the combustion chamber 1. The heat exchanger 2 is provided with a fan 4 and the like whose flow amount can be changed and adjusted, and the heat exchanger 2 is supplied with water from a domestic water supply or the like, for example, and receives hot water from a hot water tap. The hot water path 6 is respectively connected, and the water inlet path 5 is provided with a water flow rate sensor 7 as a water flow state detecting means for detecting a water flow rate to the heat exchanger 2 and an input water temperature thermistor 8 for detecting an input water temperature. The tapping path 6 is provided with a tapping temperature thermistor 9 for detecting tapping temperature.

In the fuel supply passage 10 for the burner 3, an electromagnetically operated on-off valve 11 for intermittently supplying fuel, and an electromagnetic operation as a combustion amount adjusting means NT capable of changing and adjusting a fuel supply amount (a combustion amount of the burner 3). In the vicinity of the burner 3, there is provided an igniter 13 as an ignition means for performing an ignition operation on the burner 3, and an ignition state detection for detecting whether or not the burner 3 has been ignited. And a frame rod 14 as means. As shown in FIG. 6, the gas amount control valve 12 is configured to change and adjust the gas supply amount (combustion amount) to the burner within a predetermined adjustment range.

The remote controller R is provided with an operation switch 15 for instructing start / stop of the operation of the hot water supply unit K, a temperature setting switch 16 as a temperature setting means capable of changing and setting a target temperature for tapping, a tapping temperature and a target. A display unit 17 for displaying a temperature or the like, an operation lamp 18 for displaying an operation state,
The apparatus is provided with an abnormality display lamp 19 and the like which are turned on when an abnormal state as described later occurs.

The control section H includes a microcomputer, and performs hot water combustion control means 100 for performing hot water combustion control during hot water supply, warm combustion control means 101 for performing warm combustion control during hot water supply standby, The control means includes a heat retention control check means 102 for checking the execution of the combustion control, a correction means 103 for correcting the operation state of the fan, and a command means 104 for switching the post-purge time.

The hot water supply combustion control means 100 includes a hot water supply section K
In the state where is set to the operating state, the combustion of the burner 3 is started with the passage of water to the heat exchanger 2 and the passage of water to the heat exchanger 2 is stopped. Control is performed so as to stop the combustion of the burner 3, and when the flow of water to the heat exchanger 2 is detected, the hot water supply combustion control for adjusting the combustion amount of the burner 3 so that the outlet temperature becomes the target temperature is executed. It is configured to be. Specifically, in the hot water supply combustion control, the control unit H performs the following control operation.
That is, after the operation state is set in accordance with the ON operation of the operation switch 15, the flow rate detected by the flow rate sensor 7 in response to the opening operation of the hot water tap exceeds the set flow rate and the flow rate to the heat exchanger 2 is increased. When the water flow state is detected, the water flow operation by the fan 4 is started, the intermittent valve 11 and the gas amount control valve 12 are opened, and a spark is generated by the igniter 13 to ignite the burner 3. Is started, and when the ignition state is detected by the frame rod 14, the ignition operation by the igniter 13 is ended. Then, based on the detection information of each of the incoming water temperature thermistor 8, the outgoing water temperature thermistor 9, and the flow rate sensor 7, and the information on the target temperature set by the temperature setting switch 16, the tap water temperature is set to the target temperature. The required combustion amount of the burner 3 is calculated by calculation, and the gas amount control valve 1 is adjusted so that the gas amount corresponds to the calculated combustion amount.
In addition to controlling the air flow of the fan 2, the air flow of the fan 4 is adjusted and controlled so that the air flow of the fan 4 is in an appropriate combustion state with respect to the adjusted gas amount. In this way, hot water at the target temperature is supplied from the hot water supply path 6.

The fan 4 is provided with an electric fan motor 4a, and based on a control signal from the control unit H for the fan drive unit 4b, changes the drive power for the fan 4 and adjusts the rotation speed, that is, the ventilation. The amount is adjusted. For example, when an AC motor is used, the firing angle of the thyristor is changed and adjusted. When a DC motor is used, the driving power (current conduction ratio) is changed and adjusted by changing the duty ratio of the pulse driving current. become.
The rotation speed of the fan motor 4a is measured by the rotation speed sensor 4c and fed back to the control unit H.

Then, the warming combustion control means 101
In a standby state in which hot water supply is stopped, that is, in a state in which the flow of water to the heat exchanger 2 is stopped, when the set condition for starting the warming combustion is satisfied, the combustion of the burner 3 is started to stop the warming combustion. When the set condition is satisfied, the warming combustion control for stopping the combustion of the burner 3 is executed.

More specifically, a hot water temperature thermistor 20 is provided as hot water temperature detecting means for detecting the temperature of hot water in the heat exchanger 2. When the detected value of the hot water temperature thermistor 20 is equal to or less than the set lower limit in the state where the temperature is stopped, it is determined that the set condition for starting the warmed combustion is satisfied, and the combustion of the burner 3 is started. When the detection value of the hot water temperature thermistor 20 is equal to or more than the set upper limit, it is determined that the set condition for stopping the warming combustion is satisfied, and the combustion of the burner 3 is stopped. In this way, in the hot water supply standby state, the temperature of the hot water in the hot water path inside the hot water supply device is prevented from lowering, and hot water of the target temperature can be discharged as quickly as possible at the time of re-water supply. .

The hot water temperature thermistor 20 is provided at a portion of the hot water passage in the heat exchanger 2 which is easily heated by the combustion of the burner 3 and in which the hot water temperature is liable to drop during standby of hot water supply. I have. That is, as shown in FIG. 2, the heat exchanger 2 is a state in which a plurality of fin tube type heat exchange pipe sections 2a are vertically stacked and extends over the left and right side walls 1A and 1B constituting the combustion chamber 1. Arranged in
Further, they are connected to each other by a plurality of U-shaped pipes 2b on the outer sides of the left and right side walls 1A and 1B so that they form a series of pipes connected in a meandering manner.
Further, the hot water temperature thermistor 20 is provided in the U-shaped tube 2b located near the heat exchange pipe portion 2a located on the lower side.

In the initial stage of installation of the apparatus, after the condition of water passing through the heat exchanger 2 is detected by the water flow rate sensor 7 at the initial stage of the installation of the apparatus, the heat keeping control means 102 keeps the temperature keeping until the set condition for starting the warming combustion is satisfied. It is configured to control combustion control. That is, if the warming combustion control is executed immediately after the hot water supply device is newly installed and the operation switch 15 is turned on, the hot water keeping water control is started before the water flow to the heat exchanger 2 is started. When the combustion of the burner 3 is started based on the detection information of the temperature thermistor 20, the burner 3 is heated in a state where hot water does not exist inside the heat exchanger 2 and becomes a so-called idle-fired state. In such a case, the flow of water to the heat exchanger 2 is detected, and the hot water supply combustion control is executed. After the passage of water is stopped, the warmed combustion control is executed so that the warmed combustion control is suppressed.

The control unit H is configured to control in the warming combustion control in an operation state different from the operation state in the hot water supply combustion control. More specifically, in the warming combustion control, the gas amount control valve 12 is controlled in a smaller adjustment range than the combustion amount adjustment range in the hot water supply combustion control.
In the hot water supply combustion control, when the ignition time of the igniter 13 is started and the ignition time is detected by the flame rod 14 or more, the abnormality notification operation is performed when the ignition time has elapsed. Is configured to
In the insulated combustion control, the abnormality notification operation is not performed even when the ignition time of the igniter 13 is started and the ignition time is detected by the flame rod 14 even if the set time for ignition has elapsed. When the ignition set time or more has elapsed, the ignition operation of the igniter 13 is stopped, and after the set standby time has elapsed,
It is configured to execute the ignition operation again.

In each of the hot water supply combustion control and the warming combustion control, when the combustion of the burner 3 is stopped, the control unit H continues the ventilation of the fan 4 for a set time at the maximum rotation speed. After that, the heat exchanger is configured to execute a post-purge to stop the ventilation by the fan 4, and as a set time for executing the post-purge, the heat exchanger is cooled by the post-purge after the combustion of the burner 3 is stopped in the warming combustion control. It is set so as to be short enough to keep the temperature (for example, about 5 seconds). In addition, every time the hot water supply combustion operation reaches the set number of times (100 times), that is, once every 100 times of the hot water supply operation, as a set time for executing the post-purge, the driving of the fan 4 is performed instead of the heat retention state maintaining time. It is configured to switch and set to a long operation stabilization time (for example, about 75 seconds) sufficient to stabilize the state. This operation is performed by the command means 10.
4 corresponds to the switching command.

When the post-purge is executed for a long time after the operation is switched to the operation stabilization time, the correction means 103 keeps the rotation speed of the fan motor 4a stable.
The difference between the drive power (flow rate) when control is performed to reach the maximum rotation speed (an example of the set rotation speed) and the drive power (flow rate) when the long-time post-purge was executed last time. Based on the deviation, it is determined whether the ventilation state of the ventilation path by the fan 4, for example, whether the intake portion or the exhaust tube portion is clogged with dust and the ventilation resistance is increased, and if the ventilation resistance is increased, The target rotation speed of the fan 4 in the combustion control is configured to be increased. More specifically, the initial characteristic of the target rotation speed of the fan 4 with respect to the change in the combustion amount of the burner 3 is set as a characteristic shown by a solid line in FIG. 7, and the deviation is determined when exhaust clogging or the like is determined. When the absolute value is equal to or greater than the set value (the absolute value is equal to or greater than the set value when the deviation is positive), the target rotation speed with respect to the maximum combustion amount is increased by the set amount ΔN, and the characteristic is connected with the minimum value by a straight line (FIG. 8 (see the dashed line).
When the state where the deviation is large continues, such a change adjustment is repeated until the rotation speed reaches the upper limit rotational speed, and exhaust clogging is eliminated, and when the deviation becomes small (the absolute value is set when the deviation is negative). When the value becomes equal to or less than the value, the target rotational speed is reduced by the set amount.

Next, the control operation of the control unit H will be described with reference to the control flowcharts shown in FIGS. 3, 4, and 5. When the power is turned on to the water heater, the operation switch 15
Is not ON, the heat retention flag is set to "OF".
The state is set to the "F" state and waits (steps 1 and 2).
Then, after the operation switch 15 is turned ON, as the hot water tap is opened, the detection value of the water flow sensor 7 exceeds the set water flow, and the flow (water flow) to the heat exchanger 2 is detected. Then, the hot water supply combustion control is executed. First, a normal ignition operation is performed on the burner 3 (step 4). That is, the intermittent valve 11 is opened, and the fuel supply amount to the burner 3 is set to the preset normal combustion ignition combustion amount, specifically, as shown in FIG. The gas amount control valve 12 is controlled so that the amount of combustion is slightly lower than the flow rate of the igniter 13 and the ventilation amount of the fan 4 is adjusted so that the amount of ventilation is suitable for the amount of combustion at that time. Is started, and the burner 3 is ignited.
If the ignition is not confirmed by the flame rod 14 even after the ignition operation has started for a set time (several seconds) after the start of the ignition operation, the ignition operation is stopped. The display lamp 19 is turned on to set an interlock state (steps 6 to 11). In other words, an inoperative state in which no switch is operated in consideration of operational safety is established.

The ignition is normally performed, and the flame rod 14
When the ignition is confirmed, the count value n of the hot water supply combustion counter is counted up (step 12), and the detection information and the temperature setting of each of the tap water temperature thermistor 9, the incoming water temperature thermistor 8, and the flow rate sensor 7 are set. Based on information on the target temperature by the switch 16 and the like, the required combustion amount of the burner 3 for setting the tap water temperature to the target temperature is calculated (step 1).
3) The drive of the gas amount adjusting valve 12 is controlled so that the gas amount matches the required combustion amount, and the ventilation amount of the fan 4 corresponds to the combustion amount of the burner 3 based on the characteristics shown in FIG. Control so that proper ventilation is achieved (Step 1)
4). Accordingly, the combustion amount of the burner 3 is changed within the adjustment range as shown in FIG. 6 according to the temperature information of the hot and cold water, the water flow amount information and the like.

Thereafter, the hot water combustion control is executed until the hot water tap is closed and the water flow is no longer detected, or the operation switch 15 is turned off (steps 15 and 1).
6). Even if the operation switch 15 is in the ON state, if the water flow is not detected, it is determined whether or not the heat retention flag is set to the “ON” state. In, the heat retention flag is set to “OF
Since the state is set to the "F" state, the flow returns to step 1 to be in a standby state until the water flow is detected.

When the hot water supply plug is closed and the detection value of the water flow rate sensor 7 falls below the set water amount while the hot water supply combustion control is being executed, the heat retention flag is set to "ON" (steps 15 and 16). When the operation switch 15 is turned off, the heat retention flag is set to the "OFF" state (steps 16 and 18), and the combustion of the burner 3 is stopped (step 19).

At this time, if the count value n of the hot water supply combustion counter is not 100, the ventilation by the fan 4 is continued at the maximum rotation speed for the time (about 5 seconds) set as the heat retention state maintenance time. After performing the time post-purge, the fan 4 is stopped, and the hot water supply standby state is set (steps 20 and 21). And the count value is 100
Then, after the combustion of the burner 3 is stopped, a long-time post-purge in which the ventilation by the fan 4 is continued for a time (about 75 seconds) set as the operation stabilization time is executed (steps 20 and 22). At this time, the ventilation amount of the fan 4 is adjusted to the maximum ventilation amount, and when the time sufficient to stabilize the rotation speed of the fan 4 elapses (for example, after 60 seconds), the correction of the target rotation speed of the fan 4 as described above. The control is executed (step 23), and thereafter, the count value n is reset to 0, and a hot water supply standby state is set (step 24).

FIG. 5 shows a flowchart of the correction control. In the post-purge, the drive power (flow rate) is changed and adjusted by the feedback control based on the detection information of the rotation speed sensor 4c so that the fan 4 reaches the maximum rotation speed. The deviation from the driving power during the previous long-time post-purging is obtained, and if it is determined that the driving power has decreased by a set value or more, it is determined that the ventilation resistance has increased and the ventilation path has been blocked. In this case, the change characteristic of the target rotation speed of the fan with respect to the combustion amount of the burner 3, as shown in FIG. 7, is changed to a side where the maximum rotation speed increases by ΔN.
In addition, every time the correction control is performed, if the clogging state is determined, the increase correction is repeatedly performed until the upper limit rotational speed is reached, and if it is determined that the clogging is eliminated and the ventilation resistance is reduced, The characteristic is changed so that the maximum target rotation speed decreases by ΔN (steps 231 to 235).

As described above, the operation switch 15 is turned on.
When the operation is performed and the hot water supply combustion control based on the water flow detection is being performed, the water flow is not detected, and the combustion of the burner 3 is stopped.
The operation switch 15
Is not ON, or the operation switch 15
Even if is turned ON, if the water flow is not detected, the heat retention flag is set to “OFF”.

Then, when the operation switch 15 is ON and the water flow is not detected, if the heat retention flag is set to the "ON" state, the heat retention combustion control is executed (step 25). The hot water temperature thermistor 20
When it is determined based on the detection information that the detected value Tx has become equal to or lower than a set value (set lower limit value) lower than the set temperature α by the set amount α (set lower limit value), the heat-holding ignition operation of the burner 3 is executed. (Steps 26 and 27). That is, the intermittent valve 1
1 is opened, and the fuel supply amount to the burner 3 is lower than the preset combustion set amount for the heat retention time ignition, specifically, as shown in FIG. The gas amount control valve 12 is controlled so that the amount of combustion on the flow rate side is achieved, and the ventilation amount of the fan 4 is adjusted so that the ventilation amount is suitable for the combustion amount at that time.

After the ignition operation by the igniter 13 is started, the flame rod 14
If the ignition is not confirmed in step, the ignition operation is stopped and the ignition operation is executed again (steps 28 to 32). When such a non-ignition state is repeated three times, the ignition operation is performed again after waiting for a set standby time (step 33).

When the ignition is normally performed and the ignition is confirmed by the frame rod 14, the gas amount adjusting valve 12 is controlled so that the combustion amount of the burner 3 becomes the minimum value of the adjustment range, and
Control the flow rate of the fan 4 to the minimum value (step 3
4). If the water flow is not detected and the operation switch 15 is not turned off, the hot water temperature thermistor 2 is used.
When it is determined that the detected value Tx of 0 is equal to or higher than a set value (set upper limit value) higher than the target temperature Ts for hot water supply by the set amount β, the heat keeping combustion of the burner 3 is stopped and the heat keeping state maintaining time is set. After performing a short-time post-purge for continuing the ventilation by the fan 4 at the maximum number of revolutions for about 5 seconds (approximately 5 seconds), the fan 4 is stopped, and the process returns (steps 35 to 40). By shortening the time for performing the post-purge, the temperature of the hot water cooled and kept warm by the heat exchanger 2 is prevented from lowering. still,
When the hot-water tap is opened and the water flow is detected during the execution of the heat-retaining combustion, the process proceeds to step 5 to execute the hot-water combustion control (step 35). If the operation switch 15 is turned OFF during the execution of the heat-retention combustion, the heat retention flag is set to the "OFF" state to stop the combustion of the burner 3, and after the post-purge is executed for a short time, the fan is turned off. Stop and return (step 36,
41, 38, 39, 40).

The judgment temperature (set lower limit value) as the condition for starting the warming combustion is a temperature lower than the target temperature Ts for tapping by the set amount α, and the judgment temperature (set upper limit value) as the stop condition is the temperature for tapping. Are respectively higher than the target temperature Ts by the set amount β.
When the target temperature Ts is changed and set based on the above operation, the target temperature Ts is changed accordingly, and the hot and cold water in the hot water path inside the device is heated and kept at a temperature close to the target temperature Ts.

Therefore, in the hot water supply standby state in which the hot water supply is stopped, the hot and cold water in the pipeline inside the heat exchanger 2 is always kept at the target temperature Ts or a temperature close to the target temperature Ts. Hot water having the target temperature Ts or a temperature close to the target temperature is quickly supplied, which makes it easy to use.

[Other Embodiments] (1) In the above embodiment, the command means is such that the post-purge time is automatically switched every time the number of times of hot water combustion reaches 100 times. The set number of times is not limited to “100”, but may be any number as long as it is plural times. Further, instead of such a configuration, a configuration may be employed in which the post-purge time is automatically switched every time the set elapsed time elapses. It is also possible to adopt a configuration in which the switching is instructed, and the command means can be implemented in various configurations.

(2) In the above-described embodiment, the correction control of the target rotation speed of the fan is executed every time the post-purge is executed for a long time. The configuration may be such that the correction control is performed every time the purge is performed a set number of times, or such a configuration may not be performed.

(3) As a setting condition for stopping the warming combustion, the warming combustion may be automatically stopped when a set time has elapsed since the start of the warming combustion. As the operating condition for the insulated combustion to be learned in the above, the set time for the insulated combustion may be changed.

As a specific control operation in this embodiment, the determination operation for stopping the warming combustion in step 37 in the flowchart of FIG. 4 is not a determination based on the temperature, but whether the set time has elapsed from the start of the warming combustion. , Can be replaced by time-based determination.

(4) In the above-described embodiment, the condition for starting the warming combustion is that the detection value of the warming water temperature thermistor 20 is lower than a temperature lower than the target temperature by a set amount. Instead of the configuration, the following configuration may be adopted.

The condition may be that the detected value of the hot water temperature thermistor 20 is lower than a predetermined temperature set in advance.

Further, the detected value of the hot water temperature thermistor 20 when the hot water supply combustion control is being executed is stored, and when the detected value falls below a temperature lower than the stored value by a set amount, the above described value is obtained. It is good also as a structure which starts warm combustion.

(5) In the above embodiment, the hot water temperature thermistor for detecting the temperature of hot water in the heat exchanger 2 is used as the hot water temperature detecting means for setting the set conditions for starting and stopping the warming combustion. Although the case where 20 is provided is illustrated,
Instead of such a configuration, a configuration may be adopted in which the heat retention combustion control is executed based on the detection information of the tapping water temperature thermistor 9.

(6) In the above embodiment, the water inlet 5 and the hot water outlet 6 are respectively connected to the heat exchanger 2, and the entire amount of water supplied from the water inlet 5 is heated by the heat exchanger 2. The hot water is supplied from the hot water supply path 6 after the hot water supply, but instead of such a configuration, the following configuration may be adopted.

As shown in FIG. 8, the water inlet 5 and the hot water outlet 6 are connected via a bypass 30, and the bypass 30 is provided with an intermittent bypass valve 31. Outlet hot water thermistor 32 for detecting hot water temperature
And a mixed water temperature thermistor 33 for detecting the temperature of the mixed water, a state in which the bypass valve 31 is opened to supply a large amount of relatively low-temperature water, and a state in which the bypass valve 31 is closed to supply the high-temperature water. When the bypass valve 31 is opened, in the hot water supply combustion control, the amount of combustion of the burner 3 is controlled by the detection information of the outlet hot water temperature thermistor 32 and the target temperature. Then, based on the detection information of the mixed hot water temperature thermistor 33, the combustion amount of the burner 3 is feedback-controlled so that the mixed hot water temperature becomes the target temperature.

Alternatively, as shown in FIG.
A mixing valve 34 whose distribution ratio can be changed and adjusted is provided at the junction where the heat exchanger 2 and the hot water outlet path 6 meet. The configuration may be such that the combustion amount of the burner 3 is adjusted so as to maintain the temperature, and the mixing ratio of the mixing valve 34 is adjusted and controlled such that the temperature of the mixed hot water reaches the target temperature.

(7) In the above embodiment, when executing post-purge after stopping combustion of the burner during the heat-retaining combustion control, the ventilation volume of the fan is set to the maximum ventilation volume, but it is set to a value smaller than the maximum ventilation volume. May be set.

(8) In the above embodiment, when the non-ignition state of the burner is detected in the warming combustion control, the ignition operation is executed again after waiting for a set standby time. Instead of the configuration, for example, the ignition operation may be performed by increasing the amount of combustion for warming-point ignition, or the abnormality notification operation may be performed when a non-ignition state is detected.

(9) In the above embodiment, as the hot water supply combustion control, the burner 3 is burned in accordance with the flow of water to the heat exchanger 2, and the combustion amount of the burner 3 is adjusted so that the hot water temperature reaches the target temperature. However, instead of such a configuration,
The combustion amount of the burner 3 may be set to be constant, and a water amount adjustment valve that can change and adjust the water flow amount to the heat exchanger 2 may be controlled.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a water heater.

FIG. 2 is a perspective view of a heat exchanger.

FIG. 3 is a flowchart of a control operation.

FIG. 4 is a flowchart of a control operation.

FIG. 5 is a flowchart of a control operation.

FIG. 6 is a diagram showing a combustion amount adjustment state.

FIG. 7 is a diagram showing an adjustment state of a target rotation speed.

FIG. 8 is a schematic configuration diagram of a hot water supply unit according to another embodiment.

FIG. 9 is a schematic configuration diagram of a hot water supply unit according to another embodiment.

[Explanation of symbols]

 Reference Signs List 2 heat exchanger 3 burner 4 fan 4b fan driving means 4c rotation speed detecting means 5 water inlet path 6 tap water path 20 hot water temperature detecting means 104 command means H control means

Claims (7)

[Claims] 1. A heat exchanger for heating water for heating supplied water to discharge hot water, a burner for heating the heat exchanger, a fan for passing combustion air through the burner, and a burner for the burner. And control means for controlling the operation of the fan, wherein the control means starts burning the burner as water flow to the heat exchanger is started, and the water flow is stopped. When the hot water supply combustion control for stopping the combustion of the burner is executed, the ventilation is performed by the fan in accordance with the combustion of the burner, and the setting is performed when the combustion of the burner is stopped. A hot-water supply device configured to continue ventilation by a fan for a time and then perform post-purge to stop ventilation by the fan, wherein the control unit stops the flow of water to the heat exchanger. ing In the state, the combustion of the burner is started when the set condition for starting the warm combustion is satisfied, and the warm combustion control for stopping the combustion of the burner when the set condition for stopping the warm combustion is satisfied is executed. The heat exchanger is cooled by the post-purge after the combustion of the burner is stopped in the heat-retention combustion control, as the set time for executing the post-purge in each of the hot water supply combustion control and the heat-retention combustion control. The post-purge execution time is set as a set time for executing the post-purge based on the switching command by the command means, and the driving state of the fan is stabilized instead of the heat-retention state maintaining time. A water heater configured to set a long enough operation stabilization time. 2. A control device, comprising: a rotation speed detection unit that detects a rotation speed of the fan; and a fan driving unit that adjusts driving power to the fan so that the rotation speed reaches a target rotation speed. When performing a long-time post-purge in a state where the operation stabilization time is set, the operation of the fan driving unit is controlled so that the target rotation speed becomes a post-purge set rotation speed. And a rotational speed correction control for correcting the target rotational speed based on a deviation between the driving power at that time and the driving power in the long-time post-purge executed before that time. The hot water supply device according to claim 1, wherein the hot water supply device is configured as follows. 3. The hot water supply apparatus according to claim 1, wherein the command means is configured to automatically issue the switching command each time the number of times the hot water supply combustion control is executed reaches a set number. . 4. An input path and a tap water path are connected to the heat exchanger, respectively, and hot water temperature detection means for detecting a temperature of hot water in the tap water path or the heat exchanger is provided. When the detection value of the hot water temperature detection means is equal to or less than a set lower limit,
The hot water supply device according to any one of claims 1 to 3, wherein the hot water supply device is configured to determine that the set condition for starting the warm combustion is satisfied. 5. The control means is configured to change the set lower limit value in accordance with the changed target hot water supply temperature in accordance with the change in the target hot water supply temperature in the warming combustion control. The hot water supply device according to claim 4. 6. The warm-up combustion control, in the warm-burning control, when a warm-burn setting time elapses from the start of combustion of the burner, determines that the warm-burn stop setting condition is satisfied. The hot water supply apparatus according to any one of claims 1 to 5, which is configured as described above. 7. The control means, when a detection value of the hot water temperature detection means is equal to or more than a set upper limit value,
The hot water supply apparatus according to any one of claims 1 to 6, wherein the hot water supply apparatus is configured to determine that the set condition for stopping the warming combustion is satisfied.