JPH1019377A - Hot water heater apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water apparatus wherein hot water at set temperature or temperature near the former is supplied as possible as early upon initiation of hot water supple without complicating the construction while temperature keeping and heating hot water in the apparatus utilizing a heating function of a burner, and wherein a change in temperature of the hot water upon initiation of the hit water supply is reduced to be small to supply hot water at extremely stabilized hot water supply temperature. SOLUTION: A hot water heater apparatus is adapted to include a control part H for executing ordinary combustion control where as water supply to a heat exchanger 2 for water heating is initiated, combustion of a burner 2 is initiated while as the water supply is interrupted, the combustion of the burner 3 is interrupted. In the apparatus, the control part H is adapted to execute temperature keeping combustion control where in the state that water supply it the heat exchanger 2 is interrupted as set conditions for initiation of temperature keeping combustion are satisfied, it initiates the combustion of the burner 3 while as set conditions or interruption of the temperature keeping combustion are satisfied, it interrupts the combustion of the burner 3, and is further adapted to control in an operation state different from that in the ordinary conduits control in the temperature keeping combustion control.

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 supplied from a hot water supply line by heating water supplied through a water supply passage by burning a burner, and starting water flow to the heat exchanger. And a control means for executing normal combustion control for starting the combustion of the burner as the water is supplied and stopping the combustion of the burner as the flow of water is stopped.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned hot water supply apparatus, the normal combustion control is always executed, and after the tapping from the tapping path is stopped, until the tapping from the tapping path is started again. In this configuration, the flow of water to the heat exchanger was stopped, and the burner was kept in a combustion stopped state.

[0003]

In the above-mentioned conventional construction, if the time from when the tapping from the tapping channel is stopped to when tapping is started again becomes long, the temperature of the heat exchanger heated by the burner decreases. Then, the hot water in the heat exchanger will drop to a temperature close to the temperature of the supply water, and when the hot water is re-started, hot water of such a low temperature is discharged and the temperature is falling. 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.

[0004] As a method for solving such disadvantages, a circulation path is formed by connecting a hot water path and a water intake 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 has been one that can supply hot water (for example, Japanese Patent Application Laid-Open No. 61-116).
237).

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

Therefore, in a state where the flow of water to the heat exchanger is stopped, in a control state similar to the normal combustion control, the heating operation of the burner heats and heats the hot and cold water in the water passage inside the water heater. Although it is conceivable, in the case of such a configuration, it is not necessary to provide a circulation pump or a special circulation pipe or the like, and the configuration is simplified.However, since water flow to the heat exchanger is stopped, The hot water temperature in the heat exchanger becomes too high in a short time and hot water is discharged at the time of re-watering, or by post-purging of combustion gas of a burner which is generally performed after heating and heating.
It is conceivable that various adverse effects occur, for example, hot water heated and kept warm by radiating heat and hot water having a low temperature being discharged.

The present invention has been made in view of such a point, and an object thereof is to use a heating function of a burner to heat and heat the hot water in the apparatus while complicating the configuration. No, it is possible to supply hot water at the set temperature or a temperature close to it as early as possible at the start of hot water supply, and while using the heating function of the burner, with a reasonable configuration, It is an object of the present invention to provide a hot water supply apparatus capable of performing hot water supply at a stable tap water temperature by suppressing a change in hot water temperature to a small value.

[0008]

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 execute the warm combustion control for stopping the combustion of the burner when a set condition for stopping the warm combustion is satisfied, and in the warm combustion control, the operation in the normal combustion control is performed. It is configured to control in an operation state different from the state.

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 the combustion of the burner is started only when the water is passed through the heat exchanger, a special member for passing the water through the heat exchanger is not 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, in the above-mentioned warm combustion control, since the control is executed in an operation state different from the operation state in the normal combustion control executed in a state in which water is passed through the heat exchanger, the same as the normal combustion control is performed. By controlling in the operating state of, for example, the adverse effects such as the hot water inside the heat exchanger becoming too high or the temperature becoming low due to heat radiation are suppressed beforehand, and appropriate heat retention heating is executed. It is possible to do.

According to the second aspect of the present invention, there is provided a combustion amount adjusting means capable of changing the combustion amount of the burner, and the control means controls the combustion amount adjustment range in the normal combustion control in the insulated combustion control. The combustion amount adjusting means is controlled in the small adjustment range.

That is, in contrast to the normal combustion control which requires a large amount of combustion to heat the hot water while the hot water is flowing through the heat exchanger, the warm combustion performed when the hot water is stopped is performed. In the control, by controlling the combustion amount of the burner in a small adjustment range, it is possible to avoid inconveniences such as the hot water inside the heat exchanger becoming too hot, and to erroneously discharge hot water at the time of hot water supply. Can be prevented beforehand.

According to a third aspect of the present invention, the control means controls the combustion amount adjusting means so as to attain the set combustion amount for the normal ignition when the burner is ignited in the normal combustion control. When the ignition operation is performed on the burner in the warm-up combustion control, the combustion amount adjusting means is controlled so that the set combustion amount for the warm-up time ignition is smaller than the set combustion amount for the normal-time fire. ing.

In general, at the time of the ignition operation of the burner, it is necessary to set the ignition combustion amount to be larger than the minimum combustion amount in the adjustable range in order to reliably perform the ignition. If the set combustion amount for normal ignition in the normal combustion control is applied as it is, bumping of hot and cold water in the heat exchanger may occur, and the temperature may become extremely high in a short time. Therefore, by controlling the set combustion amount for the heat retention time ignition smaller than the set combustion amount for the normal time ignition, the occurrence of such bumping is suppressed, and the temperature of the hot and cold water in the heat exchanger is adjusted to an appropriate temperature. In addition, it is possible to prevent hot water from being discharged at the time of tapping.

According to a fourth aspect of the present invention, the combustion amount adjusting means is provided with a normal combustion control adjusting section and a warm combustion control adjusting section, respectively. In the combustion control, the control section for the normal combustion control is controlled, and in the warm combustion control, the control section for the warm combustion control is controlled.

Therefore, when executing the normal combustion control or the heat-retention combustion control, the control means controls each of the adjusting units separately, so that, for example, when the combustion amount is adjusted by the same adjusting unit. In comparison with the above, the amount of combustion can be adjusted within the range of adjustment of the amount of combustion suitable for each control. Thus, it is possible to execute appropriate heat retention heating.

According to a fifth aspect of the present invention, there is provided a temperature setting means capable of changing and setting a target temperature for tapping, and the control means controls the control so that the tapping temperature becomes the target temperature in normal combustion control. The combustion amount adjusting means is configured to be controlled.

Therefore, in the normal combustion control executed in association with the tapping, the tapping temperature is controlled so as to reach an arbitrarily set target temperature. By the heating, hot water can be discharged at the target temperature or at a temperature close to the target temperature as early as possible at the start of hot water supply, so that the user of the hot water supply user can use the device easily.

According to a sixth aspect of the present invention, there is provided a ventilation means for ventilating the combustion air to the burner. In the normal combustion control, the control means controls the normal combustion after stopping the combustion of the burner. The post-purge that continues the ventilation operation of the ventilation means is performed until the set time for use elapses, and in the heat-retaining combustion mode, after the burner is stopped from burning, the set time for heat-retention combustion is shorter than the set time for normal combustion. The post-purge will be executed until the time has elapsed.

In the normal combustion control, post-purge is executed until the set time for normal combustion elapses after the combustion of the burner is stopped, so that the combustion exhaust gas of the burner is discharged to the outside of the apparatus. And in the warming combustion control,
After the combustion of the burner is stopped, post-purge is performed for a set time for warming combustion which is shorter than the set time for normal combustion. It is possible to reduce the possibility that the temperature of the hot water that has been heated and kept warm due to the heat radiation of the vessel.
In addition, if the amount of combustion in the insulated combustion control is reduced, the amount of generated combustion exhaust gas is reduced, so that the set time for insulated combustion can be set to a short time close to zero.

According to a seventh aspect of the present invention, the control means is configured to adjust the ventilation amount of the ventilation means so as to obtain an appropriate ventilation amount according to the combustion amount of the burner.

That is, not only in the normal combustion control but also in the warming combustion control, the ventilation amount of the ventilation means is adjusted so as to be an appropriate ventilation amount in accordance with the combustion amount of the burner. At the optimum combustion state.

According to the eighth aspect of the present invention, there is provided ignition means for performing an ignition operation for the burner, and ignition state detection means for detecting an ignition state for the burner, and the control means includes the normal combustion control. In the above, when a set time for ignition has elapsed from the time when the ignition operation of the ignition means is started to the time when the ignition state is detected by the ignition state detection means, an abnormality notification operation is performed. In the warming combustion control, even if a set time for ignition has elapsed from the time when the ignition operation of the ignition means is started until the ignition state is detected by the ignition state detection means, It is configured not to execute the abnormality notification operation.

When the normal combustion control is being executed, hot water is supplied. If the burner cannot be ignited, the outlet temperature does not rise and the purpose of using the hot water cannot be achieved. And informing the user of the fact, it is possible to take measures such as stopping the tapping once and then tapping again. However, when the warming combustion control is being executed, hot water is not supplied, so that even if the burner cannot be ignited, no inconvenience will occur to the hot water supply user. In this way, it is possible to prevent unnecessary confusion of the user.

According to a ninth aspect of the present invention, in the warm combustion control, the control means controls the time from when the ignition operation of the ignition means is started to when the ignition state is detected by the ignition state detection means. When the set time for ignition has elapsed, the ignition operation of the ignition means is stopped, and after the set standby time has elapsed, the ignition operation is executed again.

In other words, if the ignition is not detected even after the set time for ignition has elapsed despite the ignition operation of the burner during the warming combustion control, the ignition operation is stopped and the abnormality notification operation is performed. The ignition operation is executed again after the set standby time elapses without execution.

Therefore, it is possible to reliably perform the heat-retaining heating by avoiding the disadvantage that the state in which the ignition operation to the burner is not performed continues for a long time.

According to a tenth aspect of the present invention, there is provided a hot water temperature detecting means for detecting a temperature of hot or cold water in a hot water path or a heat exchanger, and the control means sets a detection value of the hot water temperature detecting means. When the temperature is equal to or less than the lower limit value, it is determined that the set condition for starting the warm combustion is satisfied.

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

According to the eleventh aspect of the present invention, the control means, in the heat-retention combustion control, as the target temperature is changed, the set lower limit value corresponding to the changed target temperature. Is configured to change.

Accordingly, the set lower limit for starting the insulated combustion is changed as the target temperature for hot water supply is changed, 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 the twelfth aspect of the present invention, when the set time for warm combustion elapses from the time when the burner starts burning in the warm combustion control, the control means satisfies the set condition for stopping the warm combustion. Therefore, the burner is stopped.

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 tapping, the tapping 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 thirteenth aspect of the present invention, after the start of burner combustion in the heat-retention combustion control, the control means starts the combustion in accordance with the detected value of the hot water temperature detection means being equal to or higher than the set upper limit. It is determined that the stop condition is satisfied, and the burner combustion is stopped.

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 retention combustion operation, and to supply hot water at or near the set temperature. Become.

According to the characteristic structure of the present invention, the heat exchanger is arranged in a state in which a plurality of fin tube type heat exchange pipe portions are vertically stacked, and they are successively arranged in a meandering manner. It is configured so as to form a continuous pipeline, and the hot water temperature detecting means is provided near the pipeline portion located on the lower side.

That is, of the plurality of fin tube type heat exchange pipe sections stacked vertically, the pipe section located on the lower side has a structure in which when water is stopped and combustion of the burner is stopped, Since low-temperature water has a higher specific gravity, it tends to reach the lowest temperature in each pipe section.Moreover, when the burner is burning, it is the place that is most easily heated, so set conditions for starting warm-burning combustion in such a place By providing the temperature detecting means for detecting the set lower limit value as the set value and the set upper limit value as the set condition for stopping the combustion, etc., it is possible to execute the warming combustion control in the most appropriate state. .

[0040]

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 unit K includes a heat exchanger 2 for heating water, a gas-fired 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.

The fuel supply passage 10 for the burner 3 is provided with an electromagnetically operated on-off valve 11 for interrupting the supply of 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. 7, the gas amount control valve 12 is configured so that the gas supply amount (combustion amount) to the burner can be changed and adjusted 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 is provided with a microcomputer and comprises a normal combustion control means 100 for executing normal combustion control control during hot water supply, a warm combustion control means 101 for executing warm combustion control during hot water supply standby, Each of the warming control restraining means 102 for restraining the execution of the warming combustion control is provided in the form of a control program.

The normal 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. In addition to controlling the combustion of the burner 3 to stop, when the flow of water to the heat exchanger 2 is detected, the normal combustion control for adjusting the amount of combustion of the burner 3 so that the hot water temperature reaches the target temperature is executed. It is configured to be. Specifically, in the normal 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 12 is adjusted and controlled so as to have a gas amount corresponding to the calculated combustion amount. The ventilation amount of the fan 4 is adjusted and controlled so as to achieve an appropriate combustion state. In this way, hot water at the target temperature is supplied from the hot water supply path 6.

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 a hot water temperature detecting means for detecting the temperature of hot water in the heat exchanger 2. If the detected value of the hot water temperature thermistor 20 is equal to or lower 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 detected value of the hot water temperature thermistor 20 becomes equal to or more than the set upper limit, the burner 3 is configured to stop the combustion of the burner 3 by determining that the set condition for stopping the warming combustion is satisfied. 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 FIGS. 2 to 4, the heat exchanger 2 is configured such that a plurality of fin tube type heat exchange pipe sections 2 a are vertically stacked, and the left and right side walls 1 A, 1B, and 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. Has become. 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 flow to the heat exchanger 2 is detected by the water flow rate sensor 7 in the initial stage of the installation of the apparatus, the above-mentioned temperature keeping combustion start condition is satisfied until the set condition for starting the warming combustion is satisfied. It is configured to control the warming 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, water flow to the heat exchanger 2 is detected, and the normal 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 the warm combustion control in an operation state different from the operation state in the normal 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 normal combustion control.
In the normal combustion control, after the combustion of the burner 3 is stopped, a post-purge for continuing the ventilation operation of the fan 4 for a set time for the normal combustion is executed, and in the heat-retention combustion mode, the post-purge is performed. Is executed for a time shorter than the set time for normal combustion. Further, in the normal combustion control, the igniter 1
From the time when the ignition operation of the flame rod 3 is started, the flame rod 1
In a case where the ignition time has elapsed or more before the ignition state is detected at 4, the abnormality notification operation is executed. In the warming combustion control, the ignition operation of the igniter 13 is started. Therefore, the abnormality notification operation is not performed even if the ignition time has elapsed by the time the ignition state is detected by the frame rod 14, and if the ignition time has elapsed, the igniter 13, the ignition operation is stopped, and after the set standby time has elapsed, the ignition operation is executed again.

Next, the control operation of the controller H will be described with reference to the control flowcharts shown in FIGS.
The power switch is turned on and the operation switch 15 is turned on.
When the operation is not performed, the heat retention flag is set to the "OFF" state and the operation is on standby (steps 1 and 2). And
After the operation switch 15 is turned on and the hot water tap is opened, the detection value of the water flow sensor 7 exceeds the set water flow and water flow (water flow) to the heat exchanger 2 is detected. The normal combustion control is executed. First, a normal ignition operation is performed on the burner (step 4). That is, the intermittent valve 11 is opened, and the fuel supply amount to the burner 3 is set to a preset normal-time ignition set 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. After the ignition operation is started, if the ignition is not confirmed by the flame rod 14 even after the ignition set time (several seconds) has elapsed, the ignition operation is stopped, and if such a non-ignition state is repeated three times,
The abnormality indicator 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 tap water temperature is set to the target temperature based on the detection information of each of the tap water temperature thermistor 9, the incoming water temperature thermistor 8, and the flow rate sensor 7, and the information of the target temperature by the temperature setting switch 16. The required amount of combustion of the burner 3 is calculated (step 12), and the drive of the gas amount control valve 12 is controlled so that the amount of gas matches the required amount of combustion. The characteristics of the ventilation amount are set and stored in advance as shown in FIG. 8, and the ventilation amount of the fan 4 is controlled so as to be an appropriate ventilation amount corresponding to the combustion amount (step 13). Therefore, the combustion amount of the burner 3 is changed within the adjustment range as shown in FIG. 7 according to the temperature information of the hot water and the water flow amount information and the like.

Thereafter, the normal combustion control is executed until the water tap is closed and the water flow is no longer detected, or the operation switch 15 is turned off (steps 14 and 1).
5). 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 process returns to step 1 to be in a standby state until a water flow is detected (step 12).

When the hot water tap is closed and the detection value of the water flow rate sensor 7 falls below the set water amount during the normal combustion control, the heat retention flag is set to "ON" (steps 14 and 16). When the operation switch 15 is turned off, the heat retention flag is set to the "OFF" state (steps 15 and 17), and the combustion of the burner 3 is stopped (step 18). Even after the combustion of the burner 3 is stopped, a post-purge for continuing the ventilation by the fan 4 for a set time for normal combustion (about 1 minute) is executed (step 19). At this time, the ventilation amount of the fan 4 is adjusted to the maximum ventilation amount. When the set time for normal combustion has elapsed, the fan 4 is stopped, and the hot water supply standby state is set (steps 20 and 21). Therefore, when the operation switch 15 is turned on and the normal combustion control based on the detection of the water flow is being performed, the water flow is not detected, and the combustion of the burner 3 is stopped. It is set to the state,
When the operation switch 15 is not turned on, or
Even if the operation switch 15 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 22). 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 23 and 24). 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 ignition is not confirmed in step (1), the ignition operation is stopped and the ignition operation is executed again (steps 25 to 29). When the non-ignition state is repeated three times, the ignition operation is performed again after waiting for a set standby time (step 30).

When the ignition is performed normally and the ignition is confirmed by the frame rod 14, the gas amount control valve 12 is controlled so that the combustion amount of the burner 3 becomes the minimum value of the adjustment range.
Control the flow rate of the fan 4 to the minimum value (step 3
1). 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 has become equal to or greater than a set value (set upper limit) higher than the set temperature β by the set amount β, the warming combustion of the burner 3 is stopped (step). 32 to 35). At this time, the ventilation operation of the fan 4 is stopped at the same time as the combustion of the burner 3 is stopped (step 36). By performing a post purge,
This prevents the heat exchanger 2 from radiating heat and lowering the temperature of the kept hot water. When the hot-water tap is opened and the water flow is detected during the execution of the warm combustion, the process proceeds to step 5 to execute the normal combustion control (step 32). If the operation switch 15 is turned off during the execution of the warming combustion, the warming flag is set to the "OFF" state to stop the warming combustion of the burner 3 (steps 33 and 37).

The judging 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 judging temperature (set upper limit value) as the stop condition is the tapping temperature. 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 combustion amount of the burner 3 in the heat-retention combustion control is set to the minimum value of the adjustment range of the gas amount control valve 12. Instead to,
The following configuration may be adopted.

As shown in FIG. 9, the gas control valve 12
In a state of being connected in parallel with the (ordinary combustion gas flow control valve), provided with a thermal insulation gas flow control valve 12A, adjustment range p ₁ of the thermal insulation gas flow control valve 12A, as shown in FIG. 10 typically are set to a small volume side of the adjustment range p ₂ of the combustion gas flow control valve 12, at the time of insulation combustion control adjusts the amount of gas in the temperature-maintaining gas flow control valve 12A, the normal combustion control In some cases, the gas amount may be adjusted by the normal combustion gas amount adjusting valve 12. In this case, each of the normal combustion gas control valve 12 and the warming gas control valve 12A constitutes the combustion control means NT, and the normal combustion gas control valve 12 is used for the normal combustion control. adjusting section corresponds to NT _1, the temperature-maintaining gas flow control valve 12A is to correspond to the adjusting portion NT ₂ for thermal insulation combustion control.

Further, as shown in FIG.
Is provided with a heat retaining burner portion 3a that can burn only a part of the combustion flame portion, and the heat retaining burner portion 3a
And a normal interrupting valve 26 for interrupting the supply of fuel to a burner portion other than the heat retaining burner portion 3a. Opens the intermittent valves 25 and 26,
Combustion is performed at all the flame outlets (see FIG. 11A). During the heat-retention combustion control, the normal interrupting valve 26 is closed, and the combustion is performed only at the heat-retention burner portion 3a (see FIG. 11B). It may be.

(2) In the above-described embodiment, the set time for warming combustion in which post-purge is performed after the burner is stopped during the warming combustion control is set to zero. The post-purge may be executed by setting the combustion set time to a time shorter than the normal combustion set time, or the post-purge may be executed for the same time as the warm combustion set time. In this case, the ventilation volume of the fan may be the maximum ventilation volume, or may be set to a value smaller than the maximum ventilation volume.

(3) In the above embodiment, when the non-ignition state with respect to the burner is detected in the insulated 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.

(4) As a setting condition for stopping the warming combustion, the warming combustion may be automatically stopped when a set time has elapsed from the time when the warming combustion is started. 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 34 in the flowchart of FIG. 6 is not a determination based on the temperature, but whether the set time has elapsed since the start of the warming combustion. , Can be replaced by time-based determination.

(5) In the above embodiment, the condition for starting the warming combustion is that the detected value of the hot 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.

The detected value of the hot water temperature thermistor 20 during normal combustion control is stored, and when the detected value falls below a temperature lower than the stored value by a set amount, It is good also as a structure which starts warm combustion.

(6) 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.

(7) In the above embodiment, the water inlet 5 and the hot water outlet 6 are connected to the heat exchanger 2, respectively, 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. 12, the water inlet channel 5 and the hot water channel 6
Is connected via a bypass passage 30, and a bypass valve 31 is provided in the bypass passage 30 so as to be intermittent, and an outlet hot water thermistor 32 for detecting the hot water temperature at the outlet of the heat exchanger 2.
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, the amount of combustion of the burner 3 is controlled by feed-forward control based on the detected information of the outlet hot water temperature thermistor 32 and the target temperature when the bypass valve 31 is opened. 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 of the heat exchanger 2 and the hot water outlet path 6. In this case, 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 so that the mixed hot water temperature becomes the target temperature.

(8) In the above embodiment, when the heat-retaining combustion control is executed, the hot and cold water in the hot water passage in the apparatus is maintained in a non-flowing state. As shown in FIG. 14, a pump 35 that circulates and flows through the bypass passage 30 may be provided, and when the warming combustion control is performed, the pump 35 may be operated to circulate hot water. It should be noted that the circulation pump 35 may be of a small size such that hot water slightly moves in the hot water path.

(9) In the above embodiment, as the normal 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 tap water temperature becomes 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 perspective view of a heat exchanger.

FIG. 4 is a side view of the heat exchanger.

FIG. 5 is a flowchart of a control operation.

FIG. 6 is a flowchart of a control operation.

FIG. 7 is a diagram showing a combustion amount adjustment state;

FIG. 8 is a diagram showing an adjustment state of a ventilation amount.

FIG. 9 is a view showing a combustion amount adjusting means according to another embodiment;

FIG. 10 is a diagram showing a state of adjusting a combustion amount according to another embodiment.

FIG. 11 is a diagram showing a combustion amount adjusting means of another embodiment.

FIG. 12 is a schematic configuration diagram of a hot water supply unit of another embodiment.

FIG. 13 is a schematic configuration diagram of a hot water supply unit according to another embodiment.

FIG. 14 is a schematic configuration diagram of a hot water supply unit according to another embodiment.

[Explanation of symbols]

Reference Signs List 2 heat exchanger 2a pipe section 3 burner 4 ventilation means 5 water intake path 6 tapping path 13 ignition means 14 ignition state detection means 16 temperature setting means 20 hot water temperature detection means H control means NT combustion amount adjustment means NT _{1 for} normal combustion control regulation of the regulatory unit NT ₂ insulation combustion control

Claims (14)

[Claims] 1. A water heating heat exchanger for heating water supplied through a water inlet channel by burning a burner and tapping the hot water from a hot water outlet channel; Control means for performing normal combustion control for starting combustion of the burner and stopping the combustion of the burner as the flow of water is stopped, the control means comprising: In a state where the flow of water to the heat exchanger is stopped, the combustion of the burner is started when the set condition for starting the warming combustion is satisfied, and the combustion of the burner is started when the setting condition for stopping the warming combustion is satisfied. The hot water supply device is configured to execute warmed combustion control for stopping the combustion, and to control in the warmed combustion control in an operation state different from the operation state in the normal combustion control. 2. A combustion amount adjustment means capable of changing a combustion amount of the burner is provided, wherein the control means comprises: in the insulated combustion control, an adjustment range on a smaller side than a combustion amount adjustment range in the normal combustion control. The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is configured to control the combustion amount adjusting means. 3. The control means is configured to control the combustion amount adjusting means so as to have a set combustion amount for normal ignition at the time of an ignition operation on the burner in the normal combustion control, and At the time of the ignition operation for the burner in the warming combustion control, the combustion amount adjusting means is controlled so that the burning amount for the warming time ignition is smaller than the burning amount for the normal time ignition. Item 3. The water heater according to item 1 or 2. 4. The combustion amount adjusting means includes an adjusting section for normal combustion control and an adjusting section for heat-retention combustion control, and the control means includes the normal combustion control in the normal combustion control. The hot water supply apparatus according to claim 3, wherein the hot water supply device is configured to control a control adjusting unit, and to control the warming combustion control adjusting unit in the warming combustion control. 5. A temperature setting means capable of changing and setting a target temperature for tapping, wherein the control means controls the combustion amount adjusting means such that the tapping temperature becomes the target temperature in the normal combustion control. The hot water supply apparatus according to any one of claims 2 to 4, wherein the hot water supply apparatus is configured to: 6. A ventilation means for ventilating the combustion air to the burner, wherein the control means in the normal combustion control stops the combustion of the burner and then controls the ventilation means for a set time for the normal combustion. 2. The post-purge that continues the ventilation operation is executed, and the post-purge is executed in a shorter time than the normal combustion set time in the heat retention combustion mode. 3. The hot water supply apparatus according to any one of claims 1 to 5. 7. The hot water supply apparatus according to claim 6, wherein the control unit is configured to adjust a ventilation amount of the ventilation unit so as to have an appropriate ventilation amount according to a combustion amount of the burner. 8. An ignition means for performing an ignition operation for the burner; and an ignition state detection means for detecting an ignition state for the burner, wherein the control means comprises: When a set time for ignition has elapsed from the time when the ignition operation was started to the time when the ignition state is detected by the ignition state detection means, an abnormality notification operation is performed. In the above, the abnormality notification operation is not performed even when a set time for ignition has elapsed from the time when the ignition operation of the ignition means is started until the ignition state is detected by the ignition state detection means. The hot water supply device according to any one of claims 1 to 7, wherein the hot water supply device is configured as follows. 9. The ignition control device according to claim 1, wherein the control unit is configured to control the warm-up combustion control so that a predetermined time for ignition has elapsed from the time when the ignition operation of the ignition unit is started until the ignition state is detected by the ignition state detection unit. 9. The hot water supply apparatus according to claim 8, wherein in the case of performing the operation, the ignition operation of the ignition means is stopped, and after the set standby time has elapsed, the ignition operation is executed again. 10. A hot water temperature detecting means for detecting a temperature of hot water in the hot water path or the heat exchanger, wherein the control means, when a detected value of the hot water temperature detecting means is equal to or less than a set lower limit value,
The hot water supply device according to any one of claims 1 to 9, wherein the hot water supply device is configured to determine that the set condition for starting the warm combustion is satisfied. 11. The control means is configured to change the set lower limit value in accordance with a change in the target temperature in the insulated combustion control as the target temperature is changed. The hot water supply device according to claim 10. 12. The control means, when a set time for warm combustion elapses from the time when the burner starts burning in the warm combustion control, determines that the set condition for stopping the warm combustion is satisfied. The hot water supply apparatus according to any one of claims 1 to 11, wherein the hot water supply apparatus is configured as follows. 13. 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 apparatus according to any one of claims 1 to 12, wherein it is configured to determine that the set condition for stopping the warming combustion is satisfied.
The hot water supply device according to the item. 14. The heat exchanger is arranged such that a plurality of fin tube type heat exchange pipe portions are arranged one above the other, and they form a continuous pipe line in a meandering manner. The hot-water supply device according to any one of claims 10 to 13, wherein the hot-water temperature detecting means is provided near the heat exchange pipe portion located on a lower side.