JPH1137557A - Hot-water supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-water supply which enables the supply of the hot-water of the temperature of the target temperature or near to it quickly and steadily at the start of hot-water supply without increasing the number of components in case the target temperature of the hot-water supply does not match with the temperature inside a heat exchanger. SOLUTION: A control means H executing the normal combustion control of starting the combustion at a burner 3 when the water is started to flow through a heat exchanger 2 and stopping the combustion at the burner 3 when the water flow is stopped, executes the thermally insulating combustion control starting the combustion at the burner 3 when the setting condition of starting the thermally insulating combustion is satisfied and stopping the combustion at the burner 3 when the setting condition of stopping the thermally insulating combustion is satisfied, stable hot-water temperature is set based on the detected value of hot-water temperature by the hot-water temperature detecting means Y K in the execution of normal combustion and the thermally insulated combustion control is executed with the setting condition of thermally insulating combustion based on the steady value of the hot-water temperature.

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 through a water inlet channel by burning a burner and discharging the water from a hot water channel, and a combustion device capable of changing the combustion amount of the burner. And controlling the combustion amount control means so that the burner starts burning as the water flow to the heat exchanger is started, so that the hot water supply temperature reaches the target temperature. The present invention relates to a hot water supply device comprising: control means for executing normal combustion control for stopping combustion of the burner as water is stopped.

[0002]

2. Description of the Related Art Such a hot water supply apparatus is conventionally known. In a conventionally known apparatus, water supply to a heat exchanger is restarted after hot water supply is normally stopped by combustion control, and the hot water supply is restarted. Until the normal combustion control is performed, the burner is maintained in the combustion stopped state. However, in such a conventional apparatus, when the time from when the hot water supply is stopped to when the hot water supply is restarted becomes longer, the temperature of the heat exchanger heated by the burner decreases, and when the hot water supply is started again,
There is a disadvantage that it takes time to heat the heat exchanger having the low temperature supplied with the hot water and to lower the temperature by the burner to raise the hot water temperature to the desired temperature.

[0003] Therefore, a circulation path is formed by connecting the water inlet path and the hot water path, and in a state where hot water supply is stopped and the burner is not burning, the circulation pump is driven to operate the heat exchanger through the circulation path. And a burner is burned based on the flow of hot water to the heat exchanger to maintain the temperature of hot water in the heat exchanger as close to the desired temperature as possible. (For example, see JP-A-61-116237).
Reference).

[0004]

However, the one disclosed in the above publication requires a special piping and a circulating pump for forming a circulation path, and has a disadvantage that the number of parts is increased and the cost is increased. . Therefore, in order to eliminate such disadvantages, a hot water temperature detecting means for detecting the temperature of hot water in the heat exchanger or in the tap water path is provided, and in a state where hot water supply is stopped and water flow to the heat exchanger is stopped, When the temperature detected by the hot water temperature detecting means is lower than the target temperature by a set value based on a preset hot water supply target temperature, the burner is burned to keep the hot water in the heat exchanger warm and heated, thereby achieving the target temperature. A hot water supply apparatus has been proposed in which, when the temperature becomes higher by a set value, hot-water combustion control for stopping combustion of the burner is executed and hot water having a temperature close to the target temperature can be supplied as quickly as possible at the next hot water supply.

[0005] However, as the conditions for the start of the warming combustion and the stop of the warming combustion, the warming combustion control is executed based on the detected temperature in the heat exchanger and the hot water supply path based on the hot water supply target temperature. There is a risk that the temperature of the hot water deviates significantly from the target hot water supply temperature. That is, by the normal combustion control, the hot water supply temperature is kept close to the hot water supply target temperature. At this time, the temperature in the heat exchanger and the temperature in the hot water path differs depending on the detected position and the like. There was a problem that it did not always correspond exactly.

In this type of hot water supply apparatus, the water inlet and the water outlet are connected by a bypass that bypasses the heat exchanger.
There is a so-called bypass mixing type hot water supply device that mixes hot water discharged from a heat exchanger with water from a bypass passage so that the mixed hot water temperature becomes a hot water supply target temperature. In this case, since the temperature of the hot water in the heat exchanger and the hot water path greatly deviates from the target hot water supply temperature, it was impossible to execute the heat retention combustion control based on the target hot water supply temperature.

Accordingly, the present applicant detects and stores the temperature of hot water in the heat exchanger and the tap water during normal combustion control, and stores the temperature in a state where the flow of water to the heat exchanger is stopped. Based on the detected hot water temperature value, when the temperature inside the heat exchanger or the hot water path becomes lower than the stored temperature by a set value or less, the combustion of the burner is started, and the temperature is raised to a temperature higher than the stored temperature by the set value. Then, a hot water supply device configured to stop the combustion of the burner was filed (for example, Japanese Patent Application No. 8-178847).

However, the hot water supply apparatus of the above application is configured to store the detected hot water temperature value at a specific point in time during the normal combustion control, for example, the temperature of the hot water at the end of the previous normal combustion control. For this reason, in some cases, the stored temperature may vary, which may hinder subsequent warming combustion control. In other words, when the amount of water passing through the heat exchanger changes due to a change in the opening of the hot water tap, etc., the hot water temperature inside the heat exchanger or in the hot water path changes temporarily, or the hot water tap is slowly closed. When
When closed rapidly, the temperature in the heat exchanger and the temperature of the tap water at the end of hot water supply by the normal combustion control may be significantly different. Therefore, in the hot water supply apparatus of the above-mentioned application, there is a possibility that such an unstable temperature may be stored, and by performing the heat retention combustion control based on the stored temperature, hot water of a desired temperature is not necessarily supplied at the time of re-hot water supply. There was room for improvement in this regard.

The present invention has been made in view of such a point, and its purpose is to increase the number of parts without increasing the number of parts even when the hot water supply target temperature does not correspond to the temperature inside the heat exchanger. Another object of the present invention is to provide a hot water supply apparatus capable of stably supplying hot water having a target temperature or a temperature close to the target temperature as soon as possible at the start of hot water supply.

[0010]

According to the first aspect of the present invention, the control means for executing the normal combustion control is provided for starting the warm combustion in a state where the flow of water to the heat exchanger is stopped. When the set condition is satisfied, burner combustion is started, and when the set condition for stopping warm combustion is satisfied, warm combustion control for stopping burner combustion is executed. In other words, when the flow of water to the heat exchanger is stopped,
Since the insulated combustion control is performed, piping and a circulating pump for forming the above-described circulation path are not required, and the temperature of the hot and cold water in the heat exchanger can be maintained without complicating the apparatus. .

Further, there is provided hot water temperature detecting means for detecting the temperature of hot or cold water in the heat exchanger or in the hot water path, and the control means detects the hot water by the hot water detecting means when the normal combustion control is being executed. Since the insulated combustion control is performed based on the temperature value, even when the temperature of the hot water in the heat exchanger does not correspond to the hot water supply target temperature, the desired insulated combustion control can be performed, Moreover, the start condition or the stop condition of the warming combustion control is based on the stable hot water temperature value which is stabilized by the control means based on the hot water temperature value detected by the hot water temperature detecting means, and is based on the stable hot water temperature value. Yes, for example, since hot water supply is not based on a detected hot water temperature value at a specific point in time as in the case of finishing hot water supply by normal combustion control, hot water at a desired temperature or a temperature close thereto is more stably supplied from the start of hot water supply. Possible It made.

According to the second aspect of the present invention, there is provided a water flow detecting means for detecting a water flow to the heat exchanger,
The control means divides the flow rate detected by the flow rate detection means when the normal combustion control is being executed into each set flow rate range, and obtains a flow rate distribution in each flow rate range. The stable hot water temperature value is set based on the hot water temperature value detected by the hot water temperature detecting means corresponding to the flow rate range where the temperature is high. Therefore, the detected hot water temperature value in a state where the frequency of flowing water is low and the hot water temperature is not stable is excluded, and the stable hot water temperature value is determined based on the detected hot water temperature value in a state where the flow rate of water to the heat exchanger is stable. Value will be set,
Hot water can be supplied at a desired temperature or at a temperature close thereto more reliably from the start of hot water supply.

According to the third aspect of the present invention, the control means sets the hot water temperature value detected by the hot water temperature detecting means corresponding to the maximum frequency flow rate range in the water passage frequency distribution as the stable hot water temperature value. It is configured as follows. Therefore, in the normal combustion control, the detected hot water temperature value in a state where the amount of water flowing to the heat exchanger is most stable is set as the stable hot water temperature value, and the temperature at the temperature close to the desired temperature is more reliably determined. Hot water can be supplied.

According to the fourth aspect of the present invention, the control means is configured to average the detected hot water temperature value corresponding to the maximum frequency flow rate range to obtain the stable hot water temperature value. . Therefore, compared to setting one detected hot water temperature value corresponding to the maximum frequency flow rate range to the stable hot water temperature value, an average value in the maximum frequency flow rate range is set as the stable hot water temperature value,
Hot water can be supplied at a temperature close to the desired temperature more reliably from the start of hot water supply.

According to the fifth aspect of the present invention, the control means is configured to check the setting of the stable hot water temperature when the water passage frequency in the water passage frequency distribution is equal to or less than a predetermined frequency. Therefore, in a state where the frequency of flowing water is low and the hot water temperature is not stable, the stable hot water temperature value is not set.

According to the invention described in claim 6, a timer for measuring the time elapsed from the start of the normal combustion is provided, and when the time measured by the timer is within a predetermined time, the control means sets the stable hot water temperature. Since the setting of the value is suppressed, the stable hot water temperature value is not set in a state where the hot water temperature is not stabilized by short-time normal combustion.

According to the seventh aspect of the present invention, when the control means stops the flow of water to the heat exchanger, the hot water temperature value detected by the hot water temperature detecting means becomes the stable hot water temperature. When the temperature becomes equal to or lower than a set lower limit lower than a set value, the warming combustion control is started, and when the temperature becomes equal to or higher than a set upper limit higher than the stable hot water temperature by a set amount, the warming combustion control is stopped. Therefore, the temperature of the hot or cold water in the heat exchanger or the like is reliably prevented from dropping to a low temperature equal to or lower than the set lower limit or to a high temperature equal to or higher than the set upper limit. Hot water can be supplied at a temperature close to the desired temperature.

[0018]

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, a control unit H as control means for controlling the operation of the hot water supply unit K,
The control unit H is provided with a remote control operation unit R for instructing operation information to the control unit H and the like.

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 in the combustion chamber 1, and air for combustion passing through the burner 3. The heat exchanger 2 is provided with a fan 4 and the like that can change and regulate the amount of ventilation. The heat exchanger 2 is provided with a water inlet 5 through which water is supplied from a domestic water supply, for example, and a manually operated hot water tap. A hot water supply path 6 for supplying hot water is connected to 6a, and a hot water thermistor 7 as hot water temperature detecting means YK for detecting the temperature of hot water in the heat exchanger 2 is provided. And the waterway 5
Is provided with a flow rate sensor 8 as a flow rate detecting means for detecting a flow rate of water to the heat exchanger 2 and an input water temperature thermistor 9 for detecting an input water temperature. A hot water temperature thermistor 10 is provided as hot water temperature detecting means YK.

The fuel supply path 11 for the burner 3 is provided with an electromagnetically operated on-off valve 12 for interrupting the supply of fuel gas, and an electromagnetic solenoid as a combustion amount adjusting means capable of changing and adjusting the fuel supply amount (the combustion amount of the burner 3). An operable gas amount control valve 13 is provided, and an igniter 14 for performing an ignition operation on the burner 3 and a frame rod 15 for detecting whether or not the burner 3 is fired are provided near the burner 3. ing.

The remote control operation unit R includes an operation switch 16 for instructing start and stop of the operation of the hot water supply unit K, a temperature setting switch 17 capable of changing and setting a hot water supply target temperature Ts, and necessary information such as a hot water supply temperature and a hot water supply target temperature. Display 1 for displaying
8, an operation lamp 19 for indicating that the burner is operating, and a combustion lamp 20 for indicating that the burner 3 is burning.
It is configured with such as.

The control section H is provided with a microcomputer and comprises a normal combustion control means 100 for executing normal combustion control during hot water supply, a warm combustion control means 101 for executing warm combustion control during hot water supply standby, and a hot water temperature. Hot water temperature detecting means YK such as thermistor 7 and tap water temperature thermistor 10
The stable water temperature value (stable hot water temperature value) is set based on the plurality of detected hot water temperature values by the stable value setting means 102, and the water flow rate detected by the water flow rate sensor 8 to the heat exchanger 2 is set in advance. The flow rate distribution determining means 103 for determining the distribution frequency of water flow in each flow rate range and the restraining means 104 for controlling the setting of the stable hot water value by the stable value setting means 102 are respectively controlled by a control program. Provided in the form.

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. Normal combustion control for controlling the combustion of the burner 3 so as to stop the combustion of the burner 3 and for adjusting the combustion amount of the burner 3 so that the hot water supply temperature becomes equal to the hot water supply target temperature Ts when the flow of water to the heat exchanger 2 is detected. Is configured to execute. In particular,
After the operation state is set in accordance with the ON operation of the operation switch 16, the flow rate sensor 8 is set in accordance with the opening operation of the hot water tap 6a.
If the amount of water detected in the step exceeds the set amount of water, the fan 4
And the intermittent valve 12 is opened to open and adjust the gas amount adjusting valve 13 to the ignition gas amount, and the igniter 14 ignites the burner 3 and the flame rod 15 Confirm.

The hot water supply temperature is determined on the basis of the detection information of the incoming water temperature thermistor 9, the hot water temperature thermistor 10, the water flow rate sensor 8, and the information of the hot water supply target temperature Ts set by the temperature setting switch 17. The amount of combustion of the burner 3 required to reach the target temperature Ts is obtained by calculation, and the gas amount control valve 13 is adjusted and controlled so that the amount of gas corresponds to the obtained amount of combustion. The fan 4 is set so that it is in a combustion state appropriate for the regulated gas amount.
The ventilation amount is adjusted and controlled. In this way, hot water at the hot water supply target temperature Ts is supplied from the hot water tap 6a.

The insulated combustion control means 101 operates in a standby state in which hot water supply is stopped, that is, in a state in which water supply to the heat exchanger 2 is stopped, and when a set condition for starting insulated combustion is satisfied. 3 is configured to start the combustion of the burner 3, and to execute the warm combustion control for stopping the combustion of the burner 3 when a set condition for stopping the warm combustion is satisfied. More specifically, when the detected value of the hot water temperature thermistor 7 becomes equal to or less than a set lower limit in a state where the flow of water to the heat exchanger 2 is stopped, the set condition for starting the warming combustion is satisfied. When the detected value of the hot water temperature thermistor 7 exceeds the set upper limit, it is determined that the set condition for stopping the warming combustion has been satisfied, and the burner 3
It is configured to stop the combustion of. In this manner, in the hot water supply standby state, it is possible to prevent the temperature of the hot water in the hot water path inside the hot water supply device from dropping,
The hot water of the target temperature Ts can be supplied quickly.

The hot water temperature thermistor 7 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 for hot water supply. That is, as shown in FIG. 2, the heat exchanger 2 is in 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. , And are connected to each other by a plurality of U-shaped tubes 2b on the outer sides of the left and right side walls 1A and 1B so that they form a series of lines connected in a meandering manner. I have. And
The hot water thermistor 7 is provided in the U-shaped tube 2b located near the heat exchange pipe portion 2a located on the lower side of the U-tube 2b.

The stable temperature setting means 102 is configured to set a stable hot water temperature value based on a plurality of detected hot water temperature values by the hot water temperature thermistor 7. More specifically, when the normal combustion is started, the water flow amount Q to the heat exchanger 2 detected by the water flow amount sensor 8 and the hot water temperature thermistor 7
The detected hot water temperature Th by the flow rate frequency distribution determining means 103
, The flow rate is divided into, for example, five stages. That is, as shown in FIG. 6, when the maximum water flow rate is 20 liters / minute, the water flow rate Q of 0 to 20 liters / minute is divided into five stages, the usage frequency is counted for each flow rate range, and The detected hot water temperature value Th of the hot water temperature thermistor 7 in the flow rate range is fetched and stored while averaging the hot water temperature stored in the corresponding flow rate range. In this way, the water flow amount Q to the heat exchanger 2 and the detected hot water temperature value Th of the hot water thermistor 7 are classified into each flow rate range, and when the normal combustion is stopped, the stable value setting means 102 is activated. The hot water temperature stored in the maximum frequency flow range is set as the stable hot water temperature value Ta.

The restraint means 104 sets the stable value when the time elapsed from the start to the stop of the normal combustion is within a predetermined time, or when the frequency of water flow in each flow rate range in the normal combustion is a predetermined frequency or less. The configuration is such that the setting of the stable hot water temperature value Ta by the means 102 is suppressed. In other words, when it is difficult to set a stable value Ta due to a short normal combustion time or the like, the execution of the stable value setting unit 102 is checked by the checking unit 104.

Next, the control operation of the control unit H will be described with reference to the control flowcharts shown in FIGS.
The power is turned on to the water heater and the operation switch 16 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 16 is turned on and the hot water tap 6a is opened, the flow rate of the water flow to the heat exchanger 2 is detected when the detection value of the water flow rate sensor 8 exceeds the set water quantity and the flow rate is detected. The counter provided for each flow rate range of the frequency distribution discriminating means 103 is reset, a timer for measuring the time elapsed from the start of normal combustion is started, and the temperature data initial value flag is turned off (steps 3 to 3). 6) Execute normal combustion control.

That is, the burner 3 is ignited and the amount of combustion of the burner 3 and the fan 4 are adjusted so that the tapping temperature detected by the tapping temperature thermistor 10 becomes the hot water supply target temperature Ts set by the temperature setting switch 17. The ventilation amount is controlled (steps 7 and 8). As described above, when the normal combustion control is executed and the measurement time by the timer elapses, for example, 1 second, the flow rate Q detected by the flow rate sensor 8 and the hot water temperature value Th detected by the hot water temperature thermistor 7 are fetched (steps 9 and 10). , 11),
If the temperature data initial value flag is OFF, the initial value set as the temperature data of the entire flow rate range is set, and the flow rate frequency distribution determining means 103 sets a counter for the flow rate range corresponding to the detected flow rate Q of the flow rate sensor 8. (+1) and the detected hot water temperature value Th of the hot water temperature thermistor 7 at that time.
Is updated and stored while averaging with the temperature stored in the corresponding flow rate range, and the temperature data initial value flag is turned ON (steps 12 to 16).

If the temperature data initial value flag is ON in step 12, as shown in FIG. 6, the flow frequency distribution determining means 103 sets the counter of the flow rate range corresponding to the flow rate Q detected by the flow rate sensor 8 to (+1). Then, the average value of the detected hot water temperature value Th of the hot water temperature thermistor 7 and the temperature stored in the corresponding flow rate range is updated and stored (steps 17 and 20). As for the counter in each flow range, the maximum value is set to (+10), and if the corresponding flow counter has reached the maximum value (+10) in step 18, the counters of all flow ranges other than the corresponding flow counter are set. This control is performed until the operation switch 16 is turned off or the hot water tap 6a is closed and the water flow is no longer detected (steps 21 and 22). , FIG.
The temperature data matrix of the flow frequency distribution as shown in FIG.

In step 1, the operation switch 16 is turned on.
Even if the operation is being performed, if the water flow is not detected (step 3), it is determined whether or not the heat retention flag is set to the “ON” state (step 30). In the early stage of installation of the
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. In this way, at the initial stage of the installation of the apparatus, the heat retention combustion control is not executed.

When the hot water tap 6a is closed and the detection value of the water flow rate sensor 8 falls below the set water amount during the normal combustion control, the combustion of the burner 3 is stopped.
The heat retention flag is set to the “ON” state (steps 22 to
24), it is determined whether or not there is a flow rate range in which the time measured by the timer exceeds a predetermined time and the flow rate counter has a maximum value. In the case of the temperature stored in the flow rate range, for example, the example shown in FIG. 6, 38 degrees Celsius is set as the stable hot water temperature value Ta (Steps 25 to 27), and the apparatus is in a standby state until a water flow is detected. Further, if the operation switch 16 is turned off while the normal combustion control is being executed, the combustion of the burner 3 is stopped, and the heat retention flag is set to the "OFF" state (steps 21 and 21).
8, 29), and waits until the operation switch 16 is turned on. Therefore, when the operation switch 16 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. State, and the operation switch 16 is turned off.
F and the combustion of the burner 3 is stopped, or
Even if the operation switch 16 is turned on, if the water flow has not been detected, the heat retention flag is set to “OFF”.

When the operation switch 16 is turned on and the water flow is not detected, and the heat retention flag is set to the "ON" state, based on the detection information of the hot water temperature thermistor 7, When it is determined that the detected value Tx has become equal to or less than a set value (set lower limit value) lower than the stable hot water temperature value Ta set by the stable value setting means 102 by a set amount α, the warm combustion by the burner 3 is started. (Steps 30 to 32), the warming operation is performed so that the temperature of the hot water supplied at the time of re-hot water supply does not fall significantly below the set stable hot water temperature value Ta. If the water flow is not detected and the operation switch 16 is not turned off, the detected value Tx of the hot water thermistor 7 is equal to or more than a set value (set upper limit) higher than the set stable hot water temperature Ta by the set amount β. When it is determined that the temperature has reached, the heat retaining combustion of the burner 3 is stopped (steps 35 and 36).

In this manner, the warm combustion is performed. At this time, when the hot water tap 6a is opened and the water flow is detected, the routine proceeds to step 5 to execute the normal combustion control (step 33). When the operation switch 16 is turned off, the heat retention flag is set to "OFF" to stop the heat retention combustion of the burner 3 (steps 34, 37, 38).
The set amounts α and β are appropriately set according to the characteristics of the water heater, and may be different values or may be set to the same value.

[Another Embodiment] (1) In the above embodiment, the water inlet 5 is connected to the heat exchanger 2.
And the hot water path 6 are connected to each other, and after the entire amount of water supplied from the water inlet path 5 is heated by the heat exchanger 2, the hot water path 6
Although the configuration is such that the hot water is discharged from the hot water, the following configuration may be used instead of the above configuration.

As shown in FIG. 7, the water inlet 5 and the hot water outlet 6 are connected by a bypass 30 bypassing the heat exchanger 2, and the bypass 30 is provided with an intermittent bypass valve 31. An outlet hot water thermistor 32 for detecting the hot water temperature at the outlet portion 2 and a mixed hot water thermistor 33 for detecting the hot water temperature are provided, and the bypass valve 31 is opened to supply a relatively large amount of hot water at a relatively low temperature. When the bypass valve 31 is opened, the detection of the outlet hot-water temperature thermistor 32 is performed in the normal combustion control when the bypass valve 31 is opened. The feed amount of the burner 3 is controlled by feedforward control based on the information and the target hot water supply temperature, and the burner 3 is controlled such that the mixed hot water temperature reaches the target hot water supply temperature based on the detection information of the mixed hot water temperature thermistor 33.
This is a configuration in which the combustion amount of the fuel is controlled by feedback. In this hot water supply device, the outlet hot water temperature thermistor 32 functions as hot water temperature detecting means YK.
It may be provided inside.

Further, a mixing valve that can change and adjust the mixing ratio of hot water and water is provided at the junction of the bypass path 30 and the hot water path 6 from the heat exchanger 2 shown in FIG. The combustion amount of the burner 3 is adjusted so that the detected hot water temperature of the outlet hot water thermistor 32 is maintained at a set temperature (for example, 80 ° C.), and the mixing ratio of the mixing valve is adjusted such that the mixed hot water temperature becomes the hot water supply target temperature. It may be configured to control.

(2) In the above embodiment, the stable value setting means 102 determines the average value of the detected hot water temperature values of the hot water temperature detecting means 7 corresponding to the maximum frequency flow rate by the flow rate frequency distribution determining means 103,
That is, in the example of FIG. 6, in the flow rate range of 13 to 16 liters / minute, the temperature is 38 degrees Celsius, which is the averaged and stored hot water temperature, and is set as the stable hot water temperature Ta. In addition, the following various settings can be considered.

First, as for the averaging process of the detected hot water temperature value corresponding to the maximum frequency flow rate, the detected hot water temperature value already stored and the new detected hot water temperature value are added as in the above embodiment. In addition to dividing into two equal parts, the stable hot water temperature value Ta can be set by adding all the detected hot water temperature values detected so far, dividing the value by the number of times of detection, and performing an averaging process. When the stable hot water temperature value Ta is set based on the detected hot water temperature value corresponding to the maximum frequency flow rate, it is considered that the hot water temperature value is stable. It is also possible to set the temperature value Ta.

Further, the stable hot water temperature value Ta can be set based on the detected hot water temperature value corresponding to the flow rate range where the water flow frequency is high, without being limited to the detected hot water temperature value corresponding to the maximum frequency flow rate. Specifically, in the example of FIG. 6, the detected hot water temperature values corresponding to a plurality of flow ranges having a large number of counts, that is, two flow ranges of 9 to 12 liters / minute and 13 to 16 liters / minute. Can be averaged to obtain a stable hot water temperature value Ta. Further, a stable hot water temperature value can be set by simply averaging the detected hot water temperature values from the start of the normal combustion to the stop thereof.

(3) In the above embodiment, when it is determined that the temperature has become equal to or less than the set value (set lower limit value) lower than the set stable hot water temperature value Ta by the set amount α, the warming combustion of the burner 3 is started. When it is determined that the temperature becomes equal to or higher than the set value (set upper limit) higher than the stable hot water temperature value Ta by the set amount β, the warm combustion of the burner 3 is stopped, but the normal combustion control is stopped. When it is determined that the set time has elapsed since the start of the operation, or that the temperature has become equal to or lower than the set value (set lower limit value) lower than the set hot water target temperature Ts set by the remote control operation unit R by the set amount α, the burner 3 is activated. Setting temperature (set upper limit) higher than the stable hot water value Ta by the set amount β
When it is determined that the above has occurred, the heat retaining combustion of the burner 3 may be stopped. Further, when it is determined that the temperature becomes equal to or lower than a set value (set lower limit) lower than the stable hot water temperature value Ta by the set amount α, the heat retention combustion of the burner 3 is started, and the set time from the start of combustion of the burner 3 is set. After elapse, the heat retention combustion of the burner 3 may be stopped.

(4) In the above embodiment, the restraint means 104
With this configuration, when the measurement time by the timer is within the predetermined time and when the flow frequency is equal to or less than the set value, the double check is performed, but the check may be performed using only one of them. .

[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 flow frequency distribution data matrix.

FIG. 7 is a schematic configuration diagram of a hot water supply device of another embodiment.

[Explanation of symbols]

 2 Heat Exchanger 3 Burner 5 Water Inlet 6 Hot Water Outlet 8 Water Flow Rate Detecting Means 13 Combustion Rate Adjusting Means H Control Mean Ta Stable Hot Water Temperature Ts Hot Water Supply Target Temperature YK Hot Water Temperature Detecting Means

Claims (7)

[Claims] 1. A water heating heat exchanger for heating water supplied through a water inlet channel by burning a burner and discharging hot water from a hot water channel, a combustion amount adjusting means capable of changing a combustion amount of the burner, and As the flow of water to the heat exchanger is started, the combustion of the burner is started to control the combustion amount adjusting means so that the hot water temperature becomes the target temperature, and the flow of water is stopped. Control means for performing a normal combustion control to stop the combustion of the burner together, wherein the control means, in a state where water flow to the heat exchanger is stopped, When the set condition for starting warmed combustion is satisfied, combustion of the burner is started, and when the set condition for stopping warmed combustion is satisfied, warmed combustion control for stopping combustion of the burner is executed. In the exchanger Is provided with a hot water temperature detecting means for detecting the temperature of hot water in the hot water path, and the control means stabilizes the hot water based on the detected hot water temperature value by the hot water temperature detecting means when executing the normal combustion control. A hot water supply apparatus configured to set a stable hot water temperature value and to execute the warming combustion control according to a setting condition for warming combustion based on the stable hot water temperature value. 2. A water flow rate detecting means for detecting a water flow rate to the heat exchanger, wherein the control means detects a water flow rate detected by the water flow rate detecting means when executing the normal combustion control. The stable hot water temperature is divided based on the set flow rate ranges, and the water flow frequency distribution in each flow rate range is determined, and the stable hot water temperature is detected based on the hot water temperature value detected by the hot water temperature detecting means corresponding to the flow rate range with high water flow frequency. The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is configured to set a value. 3. The hot water temperature value detected by the hot water temperature detecting means corresponding to the maximum frequency flow rate range in the water flow frequency distribution is set to the stable hot water temperature value. A hot water supply device according to item 1. 4. The hot water supply apparatus according to claim 3, wherein the control means is configured to average the detected hot water temperature value corresponding to the maximum frequency flow rate range to obtain the stable hot water temperature value. 5. The control device according to claim 2, wherein the control means controls the setting of the stable hot water temperature value when a water passage frequency in the water passage frequency distribution is equal to or lower than a predetermined frequency. The hot water supply device according to claim 1 or 2. 6. A timer for measuring a lapse of time from the start of the normal combustion is provided, and when the time measured by the timer is within a predetermined time, the control means controls the setting of the stable hot water temperature value. The hot water supply device according to any one of claims 1 to 5, wherein the hot water supply device is configured as follows. 7. A setting lower limit value in which the control means determines that the hot water temperature detected by the hot water temperature detecting means is lower than the stable hot water value by a set amount in a state where the flow of water to the heat exchanger is stopped. 7. The thermal combustion control is started when the temperature falls below the predetermined temperature, and the thermal combustion control is stopped when the temperature reaches a set upper limit higher than the stable hot water temperature by a predetermined amount. 8.
The hot water supply device according to any one of the above.