JP6776750B2 - Combustion device - Google Patents

Description

The present disclosure relates to a combustion device, and more particularly to a combustion device that corrects a target value of a fan current.

Some combustion devices have a configuration for supplying an air flow from a fan to a heating unit such as a burner. If the fan does not provide a sufficient amount of air to the heating section, it will be difficult to operate the combustion device. To ensure that the fan provides sufficient airflow, the combustion device may correct the value of the current supplied to the fan depending on the environment in which the combustion device is installed and / or the usage of the combustion device. is there. JP-A-2003-161439 (Patent Document 1) and JP-A-2006-94575 (Patent Document 2) disclose techniques for correcting the value of the current supplied to a fan in a combustion apparatus.

Japanese Unexamined Patent Publication No. 2003-161439 Japanese Unexamined Patent Publication No. 2006-94575

In order to accurately correct the current value according to the environment, it is preferable that conditions for executing the correction are provided. For example, in Japanese Patent Application Laid-Open No. 2003-161439, the amendment is performed during post-purge.

According to the conventional technique, the correction is not executed unless the above conditions are satisfied. For this reason, when the combustion device is first installed in a new environment, there is a possibility that the period in which the correction is never executed continues for a relatively long period of time.

More specifically, when the combustion device is realized as a water heater and the heating part is realized as a burner, the current value supplied to the fan is calculated based on the behavior of the fan after the combustion operation of the burner is stabilized. It is preferable to correct it. However, in summer and the like, there is a high possibility that the water heater will not be used continuously for a long time such that the combustion operation of the burner is stable. For this reason, when the combustion device is installed in a new environment in the summer, it may occur that the correction of the current value supplied to the fan is not executed for a relatively long period of time at the beginning of the installation.

The present disclosure has been devised in view of such circumstances, the purpose of which is to accurately correct the current value supplied to the fan according to the environment in the combustion device, and to install the combustion device in a new environment. This is to avoid the situation where the fan correction is not executed for a long period of time.

According to certain aspects of the present disclosure, a heating unit for heating the heat exchanger, a fan for sending air to the heating unit, and a control unit for controlling the fan are provided, and the control unit is predetermined. When the above conditions are met, the control mode of the fan is corrected based on the value of the current supplied to the fan when the fan is rotating at a predetermined rotation speed. A combustion device is provided in which the conditions become stricter as the number of corrections increases.

Preferably, the conditions are based on the amount of drive of the fan.
Preferably, the control unit determines whether or not the conditions are satisfied based on the heating time by the heating unit or the integrated heat quantity.

Preferably, the control unit performs the correction in a predetermined period after the heating unit finishes heating.

Preferably, in the correction, the control unit uses the ratio of the measured value of the current value supplied to the fan to the reference value of the current supplied to the fan to obtain a correction coefficient for the value of the current supplied to the fan. It is configured to calculate.

Preferably, the correction factor is further calculated using the number of corrections.

According to the present disclosure, as the number of corrections increases, the conditions for executing the correction become stricter. At the beginning of installation, the number of corrections is small, and the conditions for executing corrections are not strict. For this reason, it becomes easy to perform correction according to the characteristics of the environment at an early stage at the beginning of installation. At the beginning of installation, correction is relatively easy to perform. Therefore, it is possible to avoid a situation in which the fan correction is not performed for a long period of time after the combustion device is installed in the new environment.

When the number of corrections is large, the correction is not executed unless relatively strict conditions are satisfied. Therefore, the correction can accurately reflect the usage environment of the combustion device.

It is a schematic block diagram of the bath water heater which is an example of the combustion apparatus of this disclosure. It is a schematic block diagram of the controller of a bath water heater. It is a figure which shows an example of the condition of execution of the correction in a bath water heater schematically. It is a flowchart of an example of a process executed for correction of a control mode of a fan. It is a figure for demonstrating an example of the calculation mode of a correction coefficient. It is a figure which shows the other example of the condition of execution of the correction in a bath water heater schematically. It is a figure which shows still another example of the condition of execution of the correction in a bath water heater schematically. It is a figure which shows still another example of the condition of execution of the correction in a bath water heater schematically. It is a flowchart of another example of the process performed for correction of the control mode of a fan. It is a figure for demonstrating another example of the calculation mode of a correction coefficient.

Hereinafter, embodiments of the combustion apparatus will be described with reference to the drawings. In the following description, the same parts and components are designated by the same reference numerals. Their names and functions are the same. Therefore, the detailed description of these will not be repeated.

[Rough configuration of combustion equipment]
FIG. 1 is a schematic block diagram of a bath water heater 1 which is an example of the combustion device of the present disclosure. With reference to FIG. 1, the bath hot water supply device 1 has a heat exchanger 32, a combustion burner 30, a fan 31, and a water inlet pipe 50 corresponding to a water supply channel for supplying tap water or the like in the housing 1a. A bypass pipe 60, a hot water outlet pipe 70, and a controller 100 corresponding to a control unit for controlling and monitoring each part (valve, sensor, pump, etc.) of the bath hot water supply device 1 are provided. The combustion burner 30 is an example of a heating unit for heating the heat exchanger. The heating unit is not limited to the burner as long as it can heat the heat exchanger.

The bath water heater 1 includes a controller (controller 100 of FIG. 2 to be described later) for controlling the operation of each element of the bath water heater 1. The control unit of the controller (CPU 101 in FIG. 2 described later) sets a control target value for the current value supplied to the fan 31 by using the correction coefficient. The control unit calculates (updates) the correction coefficient as a correction of the control mode of the fan 31. Conditions are set for the execution of the correction of the control mode. The condition becomes stricter as the number of corrections made so far increases. The execution conditions of the above correction will be described later with reference to FIG. 3 and the like.

Returning to FIG. 1, a bypass pipe 60 is arranged between the water inlet pipe 50 and the hot water outlet pipe 70 corresponding to the water supply channel. A distribution valve 80 for controlling the diversion to the bypass pipe 60 is inserted and connected to the water inlet pipe 50. Further, a water inlet thermistor 110 and a flow rate sensor 150 are arranged in the water inlet pipe 50. The water entry thermistor 110 detects the water entry temperature of the water supply channel, that is, the temperature of tap water. A part of the water supply amount is diverted from the water inlet pipe 50 to the bypass pipe 60 according to the opening degree of the distribution valve 80.

The heat exchanger 32 is heated by the combustion operation of the combustion burner 30. The water in the water inlet pipe 50 is heated by the heat exchanger 32. The hot water heated to a predetermined temperature is discharged from the hot water discharge pipe 70. The hot water outlet pipe 70 is connected to the bypass pipe 60 at the confluence point 75. Therefore, the hot water from the hot water pipe 70 and the water from the bypass pipe 60 are mixed, and the hot water set in the operation unit 104 is supplied to the hot water supply location including the hot water tap 190 and the bathtub 8 such as the kitchen and the bathroom. To.

The hot water outlet pipe 70 corresponding to the hot water supply passage is provided with a flow rate adjusting valve 90 and a temperature sensor 130 for controlling the hot water supply flow rate. The temperature sensor 130 detects the hot water temperature after the water from the bypass pipe 60 is mixed.

Further, a hot water pouring solenoid valve 132 for pouring hot water (supplying hot water) to the bathtub 8 is provided on the downstream side of the flow rate adjusting valve 90.

[Circulation circuit]
The bath water heater 1 of FIG. 1 includes a circulation circuit. The circulation circuit is formed so as to reach from the suction port provided in the bathtub 8 to the discharge port provided in the bathtub 8 via the heat exchanger. Specifically, the circulation circuit is provided with a return circuit indicated by the arrow “return” in the drawing and a return circuit indicated by the arrow “return”. The upstream end of the return circuit (that is, the bathtub 8 side) is connected to the suction side of the circulation adapter 81 installed in the bathtub 8. Further, the downstream end of the forward circuit (that is, the bathtub 8 side) is connected to the discharge side of the circulation adapter 81. The circulation circuit is provided with a pump 33 for circulation in the return circuit and a water level sensor 35 for measuring the water level in the bathtub 8. The water level sensor 35 detects the pressure applied to the pipe of the return circuit (more specifically, the water pressure in the pipe), and detects the water level in the bathtub 8 from the detected pressure. Further, more specifically, the return circuit is provided with a bath return temperature thermistor 34 for measuring the water temperature in the pipe in the vicinity of the water level sensor 35. The bath return temperature thermistor 34 measures the temperature of the bathtub water entering the return circuit from the bathtub 8. Further, the going circuit is provided with a bath going temperature thermistor 36 for measuring the temperature of the water discharged into the bathtub 8.

Although the water level in the bathtub 8 is indicated by the output of the pressure type water level sensor 35 provided in the middle of the circulation circuit, the water level sensor is not limited to the pressure type. Further, the mounting position of the water level sensor is not limited to the circulation circuit, and may be installed in, for example, the bathtub 8.

When the pump 33 is operated so that the water (or hot water) of the bathtub 8 circulates through the above circulation circuit, the bathtub water from the bathtub 8 is discharged from the suction port of the circulation adapter 81 to the return pipe and the heat exchanger, and , The route to the discharge port 86 of the circulation adapter 81 is circulated via the bathtub pipe. As a result, the water temperature in the circulation circuit including the bathtub 8 can be made uniform.

[Configuration of controller 100]
FIG. 2 is a schematic configuration diagram of the controller 100 of the bath water heater 1. The controller 100 sends a control signal for opening / closing the valve or driving the pump to the CPU (Central Processing Unit) 101, various valves in the bath hot water supply device 1, various pumps, and the like, and also sends various sensors (water level sensor, It includes an interface 103 for inputting a detection signal from a temperature sensor such as a thermistor, a flow rate sensor, etc., an operation unit 104, an output unit 105 for outputting information on the operation of the bath hot water supply device 1, a timer 106, and a storage unit 102. .. The CPU 101 realizes a timekeeping function by using the timer 106. The operation unit 104 includes a switch, a button, and the like for receiving a user operation (for example, an operation for inputting an instruction regarding operation, etc.) for the bath water heater 1. The operation instruction includes a water level setting value, a hot water amount setting value, or a temperature setting value when the bathtub 8 is filled with hot water.

The storage unit 102 comprises a volatile or non-volatile memory for storing programs and data. The storage unit 102 includes a target value storage unit 1021, a reference value storage unit 1022, a condition storage unit 1023, a control value storage unit 1024, a correction coefficient storage unit 1025, and a correction number storage unit 1026.

The target value storage unit 1021 stores the target value of the rotation speed of the fan 31 in the correction of the control mode of the fan 31.

The reference value storage unit 1022 stores a reference value (reference value I _0, which will be described later) of the current value to be supplied to the fan 31 when the fan 31 rotates at the target value.

The condition storage unit 1023 stores data for specifying conditions for executing correction of the control mode of the fan 31.

The control value storage unit 1024 stores a current value to be supplied to the fan 31 according to the operation status of the bath water heater 1. An example of the operation status of the bath water heater 1 is the target combustion amount of the combustion burner 30. In this example, the control value storage unit 1024 stores the amount of current to be supplied to the fan 31 as a control value for each target combustion amount.

The correction coefficient storage unit 1025 stores a correction coefficient (correction coefficient C) for the control value.
The correction number storage unit 1026 stores the number of corrections (correction number N) executed in the bath water heater 1.

Further referring to FIG. 1, in the controller 100, when the hot water tap 190 is opened with the operation start switch of the bath water heater 1 turned on, the flow rate detected by the flow rate sensor 150 is the minimum operating flow rate (MOQ). The combustion operation by the combustion burner 30 is turned on accordingly. In the hot water filling mode for the bathtub 8, the CPU 101 controls to open various valves (distribution valve 80, flow rate adjusting valve 90, and hot water pouring solenoid valve 132). As a result, pouring into the bathtub 8 is started. The CPU 101 detects the amount of hot water poured into the bathtub 8 from the output of the flow rate sensor, compares the detected amount of hot water with the hot water filling amount, and ends the hot water pouring operation based on the result of the comparison.

The CPU 101 compares the measured water level by the water level sensor 35 with the preset determination water level in a state where the bathtub 8 is filled with hot water after the hot water injection operation is completed, and based on the comparison result (measured water level ≥ determination). When it is determined that the condition of water level) is satisfied, the hot water filling mode is terminated. The CPU 101 controls each part of the bath water heater 1 according to the operation mode of the bath water heater 1. For example, when the condition is satisfied in the heat retention mode, the CPU 101 controls each part so as to keep the hot water temperature of the bathtub 8 at the set temperature.

The controller 100 includes a rotation detection unit 311 that detects the rotation of the fan 31 and a current measurement unit 312 that measures the current value supplied to the fan 31. The CPU 101 transmits a control signal to the fan 31 via the interface 103. The CPU 101 supplies a drive current to the fan 31, for example, while the combustion operation by the combustion burner 30 is turned on. The rotation detection unit 311 outputs the rotation speed of the fan 31 and the like to the CPU 101 via the interface 103. The current measuring unit 312 outputs a detected value (current value) to the CPU 101 via the interface 103.

[Fan current setting]
The setting of the current value supplied to the fan 31 will be described. The CPU 101 sets, for example, the target combustion amount of the combustion burner 30 according to the hot water supply temperature set in the bath water heater 1. The CPU 101 reads out the control value associated with the target combustion amount from the control value storage unit 1024. The CPU 101 further reads the correction coefficient from the correction coefficient storage unit 1025. The CPU 101 derives a control target value of the fan 31 by using the read control value and the read correction coefficient.

The control target value is derived, for example, as the product of the control value and the correction coefficient C according to the following equation (1).

Control target value = control value x correction coefficient C ... (1)
The CPU 101 supplies the fan 31 with an amount of current specified by the derived control target value via the interface 103.

[Specific examples of conditions]
The correction of the control mode of the fan 31 by the CPU 101 is executed when a predetermined condition is satisfied. The condition is stored in the condition storage unit 1023 (FIG. 2). FIG. 3 is a diagram schematically showing an example of the condition.

As shown in FIG. 3, in the condition storage unit 1023, the correction condition is associated with the correction number N. The correction number N is a variable used in the processing of FIG. 4 described later, and is the number of times the correction for the fan current is executed. The initial value of the number of corrections N is, for example, 0. The correction number N is stored in, for example, the storage unit 102.

More specifically, when the number of corrections N is 0 to 9, the correction condition is that the continuous heating time is 1 minute or more. When the number of corrections N is 10 or more, the correction condition is that the continuous heating time is 5 minutes or more. The “continuous heating time” is the time during which the combustion burner 30 continuously heats the heat exchanger 32.

According to FIG. 3, when the number of corrections N is 0 to 9, the condition for executing the correction is satisfied if the heating is continued for 1 minute or more, whereas when the number of corrections N is 10 or more, the heating is performed for 5 minutes or more. If it is not continuous, the correction will not be executed. That is, in the example of FIG. 3, as the number of corrections increases, the conditions for executing the correction become stricter.

The example of FIG. 3 includes two classes of “0 to 9” and “10 or more” for the number of corrections N. The conditions used in the bath water heater 1 may include correction conditions for each of the three or more classes for the number of corrections N.

[Processing flow]
FIG. 4 is a flowchart of an example of processing executed by the controller 100 in order to correct the control mode of the fan 31. The process of FIG. 4 is realized, for example, by the CPU 101 executing a given program.

As shown in FIG. 4, in step S100, the CPU 101 determines whether or not the combustion of the combustion burner 30 is completed. The CPU 101 keeps control in step S100 until the combustion is completed (NO in step S100), and when it is determined that the combustion is completed (YES in step S100), the CPU 101 proceeds to the control in step S105.

In step S105, the CPU 101 shifts the state of the bath water heater 1 to post-purge. After that, the control proceeds to step S110.

In step S110, the CPU 101 reads out the correction conditions. The correction condition is associated with the number of corrections N, as shown in FIG. The CPU 101 reads the correction number N from the correction number storage unit 1026, and reads the correction condition associated with the correction number N from the condition storage unit 1023. After that, the control proceeds to step S120.

In step S120, the CPU 101 determines whether or not the read correction condition is satisfied.

More specifically, when the number of corrections N is 0-9, the CPU 101 determines whether or not the combustion whose end is determined in step S100 has been continuously continued for 1 minute. The start time and end time of the combustion are stored in a given area of the storage unit 102, for example. The CPU 101 specifies the time measured by the combustion based on the start time and the end time. When the combustion is continuously continued for 1 minute or more, the CPU 101 determines that the above correction condition is satisfied. If the combustion does not continue for 1 minute or more, that is, if the combustion ends before 1 minute has elapsed from the start, the CPU 101 does not satisfy the above correction condition. to decide.

When the number of corrections N is 10 or more, the CPU 101 determines whether or not the combustion whose end is determined in step S100 has been continuously continued for 5 minutes. If the combustion continues for 5 minutes or more, the CPU 101 determines that the above correction conditions are satisfied. If the combustion does not continue for 5 minutes or more, that is, if the combustion ends before 5 minutes have elapsed from the start, the CPU 101 does not satisfy the above correction condition. to decide.

When the CPU 101 determines that the correction condition is satisfied, the CPU 101 advances the control to step S130. On the other hand, when the CPU 101 determines that the correction condition is not satisfied, the CPU 101 ends the process of FIG.

In step S130, the CPU 101 acquires the measured value I'measured by the current measuring unit 312. The measured value I'is the value of the current supplied to the fan 31 when the rotation speed of the fan 31 reaches the target value stored in the target value storage unit 1021.

In step S140, the CPU 101 calculates the correction coefficient C for the current value supplied to the fan 31 by using the measured value I'and the reference value I ₀ . The reference value I ₀ is stored in the reference value storage unit 1022 (FIG. 2) at the time of product shipment, for example.

FIG. 5 is a diagram for explaining an example of a calculation mode of the correction coefficient. As shown by the equation (2) in FIG. 5, the correction coefficient C is calculated as the ratio of the reference value I _{0 to} the measured value I ′.

Returning to FIG. 4, in step S150, the CPU 101 adds 1 and updates the value of the number of corrections N stored in the correction coefficient storage unit 1025. After that, the process of FIG. 4 ends.

In the process of FIG. 4 described above, whether or not the condition for executing the correction of the current value supplied to the fan 31 is satisfied in the bath water heater 1 after the combustion of the combustion burner 30 is completed (YES in step S100). (Step S120). If it is determined that the condition is satisfied (YES in step S120), the bath water heater 1 calculates a correction coefficient for the current value in step S130 and thereafter. The above conditions become stricter as the number of corrections executed so far increases.

In the process of FIG. 4, the control of step S100 is executed within a predetermined time after the combustion of the combustion burner 30 is completed. As a result, in the bath water heater 1, the correction of the control mode of the fan 31 can be executed within the period specified as the so-called post-purge. However, in the bath water heater 1, the correction does not necessarily have to be executed within the post-purge period as long as the combustion burner 30 is in the non-combustion state.

[Conditions for correction execution]
(Fig. 6)
FIG. 6 is a diagram schematically showing another example of the condition in which the correction of the control mode of the fan 31 is executed. In the example of FIG. 6, the correction number N is associated with the correction condition as in FIG. However, the correction condition of FIG. 6 is related to the integrated heat quantity. The integrated heat quantity is, for example, the heat quantity required to be supplied by the combustion burner 30 in the immediately preceding heating. In FIG. 6, the correction condition when the number of corrections N is 0-9 is that the integrated heat quantity is Q1 or more. The correction condition when the number of corrections N is 10 or more is that the integrated heat quantity is Q2 or more. Q1 and Q2 are predetermined constants. Q2 is a value larger than Q1.

According to the definition shown in FIG. 6, when the number of corrections N is 0-9, even if the accumulated heat amount does not reach Q2, the correction is executed if it reaches Q1. On the other hand, when the number of corrections N is 10 or more, even if the accumulated heat amount reaches Q1, the correction is not executed unless it reaches Q2. That is, the above condition becomes stricter as the number of corrections increases.

When the conditions shown in FIG. 6 are used, the control in step S120 of FIG. 4 is executed as follows.

More specifically, when the number of corrections N is 0-9, the CPU 101 determines whether or not the integrated heat quantity in the combustion whose end is determined in step S100 is Q1 or more. The integrated heat quantity is stored in a given area of the storage unit 102, for example. When the integrated heat quantity is Q1 or more, the CPU 101 determines that the above correction conditions are satisfied. When the integrated heat quantity is less than Q1, the CPU 101 determines that the above correction condition is not satisfied.

When the number of corrections N is 10 or more, the CPU 101 determines whether or not the integrated heat amount in the combustion whose end is determined in step S100 is Q2 or more. When the integrated heat quantity is Q2 or more, the CPU 101 determines that the above correction conditions are satisfied. When the integrated heat quantity is less than Q2, the CPU 101 determines that the above correction condition is not satisfied.

When the CPU 101 determines that the correction condition is satisfied, the CPU 101 advances the control to step S130. On the other hand, when the CPU 101 determines that the correction condition is not satisfied, the CPU 101 ends the process of FIG.

(Fig. 7)
FIG. 7 is a diagram schematically showing still another example of the condition in which the correction of the control mode of the fan 31 is executed. In the example of FIG. 7, the correction number N is associated with the correction condition as in FIG. However, the correction condition of FIG. 7 is related to the continuous operation time of the fan 31. The continuous operation time is, for example, the length of time that the fan 31 has been continuously operated (rotated) in the heating by the combustion burner 30 immediately before. The continuous operation time is an example of the driving amount of the fan. In FIG. 7, the correction condition when the correction number N is 0-9 is that the continuous operation time is T1 or more. The correction condition when the number of corrections N is 10 or more is that the continuous operation time is T2 or more. T1 and T2 are predetermined constants. T2 is a value larger than T1.

According to the definition shown in FIG. 7, when the number of corrections N is 0-9, even if the continuous operation time does not reach T2, the correction is executed if T1 is reached. On the other hand, when the number of corrections N is 10 or more, even if the continuous operation time reaches T1, the correction is not executed unless T2 is reached. That is, the above condition becomes stricter as the number of corrections increases.

When the conditions shown in FIG. 7 are used, the control in step S120 of FIG. 4 is executed as follows.

More specifically, when the number of corrections N is 0-9, the CPU 101 determines whether or not the continuous operation time of the fan 31 in the combustion whose end is determined in step S100 is T1 or more. The continuous operation time is stored in a given area of the storage unit 102, for example. When the continuous operation time is T1 or more, the CPU 101 determines that the above correction conditions are satisfied. When the continuous operation time is less than T1, the CPU 101 determines that the above correction condition is not satisfied.

When the number of corrections N is 10 or more, the CPU 101 determines whether or not the continuous operation time of the fan 31 in the combustion whose end is determined in step S100 is T2 or more. When the continuous operation time is T2 or more, the CPU 101 determines that the above correction conditions are satisfied. When the continuous operation time is less than T2, the CPU 101 determines that the above correction condition is not satisfied.

When the CPU 101 determines that the correction condition is satisfied, the CPU 101 advances the control to step S130. On the other hand, when the CPU 101 determines that the correction condition is not satisfied, the CPU 101 ends the process of FIG.

(Fig. 8)
When the bath water heater 1 is in a specific situation, the correction may be performed unconditionally after the combustion is completed. FIG. 8 is a diagram schematically showing still another example of the condition in which the correction of the control mode of the fan 31 is executed.

In the example shown in FIG. 8, the correction conditions are each of the three classes (“0”, “1-9”, and “10 or more”) for the number of corrections N, as compared with the example shown in FIG. Is associated with. In the example of FIG. 8, the correction condition when the correction number N is “0” is “no condition”.

The number of corrections N indicates a situation in which the correction has not yet been executed in the bath water heater 1. In the example of FIG. 8, after the combustion burner 30 burns for the first time (when the number of corrections is N), the correction of the control mode of the fan 31 is unconditionally executed.

[Other examples of processing flow]
FIG. 9 is a flowchart of another example of processing executed in the controller 100 to correct the control mode of the fan 31. The process of FIG. 9 includes step S102 instead of step S100 and step S105 as compared to the process of FIG.

In step S102, the CPU 101 determines whether or not the bath water heater 1 is operating in the test mode. The bath water heater 1 operates in the test mode, for example, by operating the button for the test mode in the operation unit 104.

The CPU 101 keeps control in step S102 until it is determined that the bath water heater 1 is operating in the test mode, and when it is determined that the bath water heater 1 is operating in the test mode, the control proceeds to step S110. After that, the CPU 101 executes a process for correcting the control mode of the fan 31 as necessary by the control after step S110.

According to the process shown in FIG. 9, in the bath water heater 1, even if the heating by the combustion burner 30 is not executed, if the button for the test mode is operated, the control mode of the fan 31 can be corrected. ..

In the bath water heater 1, the CPU 101 may execute both the process shown in FIG. 8 and the process shown in FIG.

[Other examples of calculation of correction coefficient]
FIG. 10 is a diagram for explaining another example of the calculation mode of the correction coefficient C. In FIG. 10, the formula (2A) and the formula (2B) are shown. In step S140 (FIG. 4 or 9), the CPU 101 may calculate the correction coefficient C by using the equations (2A) and (2B) instead of the equation (2) shown in FIG.

According to the formula (2A), the CPU 101 calculates the rate of change R using the measured value I'and the reference value I ₀ . The CPU 101 stores the calculated rate of change R as the rate of change Rc this time in the storage unit 102. The CPU 101 further stores the rate of change Rc stored in the storage unit 102 up to that point as the previous rate of change Rp in the storage unit 102.

According to the equation (2B), the CPU 101 calculates the correction coefficient C by using the current rate of change Rc, the previous rate of change Rp, and the number of corrections N.

Equations (2A) and (2B) of FIG. 10 use the number of corrections to calculate the correction coefficient C. As a result, the smaller the number of corrections N, the greater the influence of the derived correction coefficient C on the correction coefficient C of the value of the rate of change calculated in one correction.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 bath hot water supply device, 30 combustion burner, 31 fan, 32 heat exchanger, 100 controller, 102 storage unit, 103 interface, 104 operation unit, 105 output unit, 311 rotation detection unit, 312 current measurement unit, 1021 target value storage unit 1022 Reference value storage unit, 1023 Condition storage unit, 1024 Control value storage unit, 1025 Correction coefficient storage unit, 1026 Correction frequency storage unit.

Claims (6)

A heating unit for heating the heat exchanger,
A fan for sending air to the heating part and
A control unit for controlling the fan is provided.
The control unit controls the fan based on the value of the current supplied to the fan when the fan is rotating at a predetermined rotation speed when a predetermined condition is satisfied. It is configured to correct the aspect and
The condition becomes stricter as the number of times of the correction increases. The combustion apparatus according to claim 1, wherein the condition is based on the driving amount of the fan. The combustion apparatus according to claim 2, wherein the control unit determines whether or not the above conditions are satisfied based on the heating time by the heating unit or the integrated heat quantity. The combustion apparatus according to any one of claims 1 to 3, wherein the control unit executes the correction in a predetermined period after the heating unit finishes heating. In the correction, the control unit corrects the value of the current supplied to the fan by using the ratio of the measured value of the current value supplied to the fan to the reference value of the current supplied to the fan. The combustion apparatus according to any one of claims 1 to 4, which is configured to calculate a coefficient. The combustion apparatus according to claim 5, wherein the correction coefficient is further calculated by using the number of corrections.

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