JPH0771748A - Combustion apparatus and combustion controlling method - Google Patents

Abstract

PURPOSE:To properly supply the amount of air required by a burner in response to the amount of input of a fuel by providing a pressure sensor in an air passage extending in a combustion apparatus. CONSTITUTION:A pressure sensor 37 is provided in a passage for air fed by a fan 38 in a combustion apparatus 20. The pressure sensor 37 detects failures, e.g. the wind is blowing outside the apparatus 20 and clogging is produced on the air passage in the apparatus 20, and so on. A controller 32, once such failure is detected, controls the amount of air (oxygen) required for combustion by increasing/decreasing revolutions of the fan 38 and adjusting the opening of a fan damper 36 and detecting flame temperature with a flame rod 27 and supplying the proper amount of air (oxygen) into the apparatus 20 based upon a detected value. Hereby, the amount of air required for the combustion of the burner 33 is properly supplied in response to the amount of input of the fuel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus such as a water heater and a bathtub and a combustion control method therefor.

[0002]

2. Description of the Related Art A conventional combustion apparatus, such as a water heater, is constructed as shown in FIG. FIG. 7 shows a schematic configuration of the water heater. In the figure, a water heater 1 includes a number of burners 13 such as Bunsen burners in a combustion chamber inside a case 2.
The gas is supplied to these burners 13 through the proportional valve 4.

A water supply pipe 3 is provided in the water heater 1 so that water can be supplied from the outside, and a flow sensor 15 is provided in the middle of the water supply pipe 3.
The water introduced inside by the water supply pipe 3 is heat-exchanged by the heat exchanger 10, becomes hot water of a predetermined temperature, and is tapped through the tap pipe 9. The tap pipe 9 is provided with a temperature thermistor 5 and a water control valve 9a.

A fan 6 is set below the burner 13 to send the air required for combustion. Also,
When facing the flame hole of the burner 13, the frame rod electrode 7 and
An igniter electrode 8 is provided respectively.

By the combustion in the burner 13, the water introduced through the water supply pipe 9 as described above is heat-exchanged in the heat exchanger 10 to be hot water of a predetermined temperature and the burner 1
The exhaust gas from the combustion of No. 3 is exhausted through the exhaust passage 11.

A control unit 12 is provided in such a water heater 1, and the control unit 12 opens and closes the proportional valve 4 to determine the input amount of the fuel gas supplied to each burner 13. In accordance with this, for example, the rotation speed of the fan 6 is determined while observing the detection value of the air volume sensor 14 provided near the outlet of the fan 6, and the air required for combustion is sent.

That is, in such a water heater 1, when hot water is supplied at a predetermined temperature, it is necessary to burn the fuel corresponding to the determined input amount of fuel such as gas. The number of rotations of the fan for supplying the appropriate air is given in advance to the storage means of the control unit 12 in a predetermined table or calculated. Therefore, the control unit 12 monitors the signal of the air volume sensor 14,
Referring to this table, adjust the rotation speed of the fan 6,
The air required for combustion of the input fuel is sent.

Further, in the water heater 1, when the burner 13 disappears or the lift is detected by the frame rod 7, the proportional valve 4 is closed to stop the gas supply. The air amount control by the fan 13 is not based on the detection value of the air flow sensor 14 described above, but via the frame rod 7 to the control unit 1.
2, there is also a method of monitoring the flame temperature of the burner and controlling the fan rotation speed according to the change so as to perform good combustion.

[0009]

However, the conventional combustion apparatus 1 and combustion control method as described above have the following problems, respectively. First, with the air volume sensor 14,
In the method of adjusting the rotation speed of the fan 6, the water heater 1
Exhaust passage 11 when wind is blowing outside
Exhaust resistance may occur in the combustion exhaust gas discharged through the exhaust gas.

At this time, even if the fan 6 is rotating at a rotational speed corresponding to the input amount of fuel in the steady operation,
The burner 13 cannot supply sufficient air for combustion, resulting in incomplete combustion.

In such a state, not only when the wind is blowing outside the water heater 1, the air supplied from the intake port (not shown) of the case 2 by the fan 6 passes through the combustion chamber and the exhaust passage. It also occurs if there is a blockage anywhere in the air path from the exhaust to 11.

On the other hand, the frame rod 7 causes the burner 13
Of the combustion flame temperature of the fan 6
However, there is a problem in that the state of the flame does not accurately or immediately reflect the state of the air supplied by the fan 6 when controlling the number of revolutions. Therefore, there is a problem that it is not possible to perform detailed combustion control of the water heater 1.

The present invention has been made to solve the above-mentioned problems, and a combustion apparatus and a combustion control thereof, which can appropriately supply an air amount required for combustion by a burner according to an input amount of fuel. The purpose is to provide a method.

[0014]

According to the present invention, the above object is a combustion apparatus in which air is supplied to a combustion chamber by a fan and combustion exhaust gas is discharged through an exhaust passage. Is achieved by a combustion device including a pressure sensor having one end connected to the upstream side and the other end connected to the downstream side in the passage of the air introduced into the device.

Further, the above object is a combustion control method for a combustion device, wherein air is supplied to a combustion chamber by a fan, and the rotation speed of the fan is controlled to adjust the air amount. A pressure sensor is provided in the air passage of, and the air amount is controlled based on the detection value of this sensor.
Further, when the combustion flame temperature of the burner is detected and when the temperature range corresponding to a preset good combustion state is exceeded, the amount of air supplied to the apparatus is further controlled to bring the combustion apparatus into a good combustion state. It is also achieved by the combustion control method of.

[0016] Preferably, a combustion control method for a combustion apparatus, wherein air is supplied to a combustion chamber by a fan, and the number of revolutions of the fan is controlled to adjust the amount of air. A pressure sensor is installed in the passage for controlling the amount of air supplied to the device based on the value detected by this sensor, and detecting the combustion flame temperature of the burner to respond to a preset good combustion state. When the temperature exceeds the specified temperature range, the rotation speed of the fan is controlled, and /
Alternatively, a good combustion state may be achieved by opening and closing a damper that opens and closes a passage of air supplied to the combustion chamber by a fan.

When the fan rotation speed is maximum and / or the damper opening is maximum,
The supply amount of fuel gas may be reduced and the supply amount of water to be heated in the device may be reduced.

[0018]

According to the above construction, the pressure sensor is provided in the passage of the air guided by the fan in the combustion device. Therefore, the pressure sensor can detect an abnormal state in which wind blows outside the device or an air passage is blocked inside the device.

Further, when such an abnormal state is detected, the fan damper is increased or decreased by increasing or decreasing the number of revolutions of the fan to replace the excess or deficiency of the amount of air (oxygen) required for combustion, or in addition to this. The temperature is controlled by adjusting the degree of opening and the flame temperature is detected, and an appropriate amount of air (oxygen) is sent into the device based on the detected value.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the examples described below are suitable specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

FIG. 1 is a schematic configuration diagram of a water heater as an example of a combustion apparatus according to a preferred embodiment of the present invention. In the figure, in the combustion chamber inside the case 21 of the water heater 20,
A large number of burners 33 are accommodated. These burners 3
3 is, for example, Bunsen burner, all primary type burner,
A burner for dark and light combustion can be used. Gas is supplied to these burners 33 through the proportional valve 24.

A water supply pipe 23 is provided in the water heater 20 so that water can be supplied from the outside. A flow sensor 26 is provided in the middle of the water supply pipe 23 to detect the amount of water supplied from the outside.

The water introduced into the apparatus through the water supply pipe 23 is heat-exchanged by the heat exchanger 30, becomes hot water having a preset temperature, and is discharged from the hot water discharge pipe 19. There is. The tap pipe 19 is provided with a temperature thermistor 25 to monitor the tap temperature. The hot water outlet pipe 19 is provided with a water control valve 19a, and the hot water discharge amount is adjusted by adjusting the opening degree of the water control valve 19a.

Further, for example, a fan 38 made of a sirocco fan or the like is provided below the burner 33 to supply the air required for combustion to the combustion chamber in the apparatus. Although the fan 38 is disposed below the burner 33, the fan may be provided on the downstream side of the burner 33 so that air is supplied to the combustion chamber by a suction type fan. In this embodiment, the air flow sensor 34 is provided near the outlet through which the air supplied from the fan 38 is guided to the combustion chamber. Further, a damper 36 that controls the amount of air sent from the fan 38 to the combustion chamber is provided.
Further, a frame rod electrode 27 and an igniter electrode 28 are provided facing the flame holes of the burner 33, respectively.

By the combustion of these burners 33, the water introduced through the water supply pipe 19 as described above is converted into the heat exchanger 30.
Is heat-exchanged to obtain hot water having a predetermined temperature. Further, the exhaust gas generated by the combustion of the burner 33 is exhausted to the outside through the exhaust passage 31.

A control unit 32 is provided in such a water heater 20. The controller 32 opens and closes the proportional valve 24 in the steady operation of the water heater 20 to control the remote controller 3
The input amount of the fuel gas supplied to each burner 33 is determined in accordance with the set temperature and the amount of hot water discharged set by 9, etc. Further, in accordance with this, for example, the rotation speed of the fan 38 is determined while observing the detection value of the air flow sensor 34 provided near the outlet of the fan 38, and the air required for combustion is sent.

Specifically, in such a water heater 20, when supplying hot water at a predetermined temperature, the proportional valve 24 is opened / closed for a fuel such as a predetermined gas to determine its input amount. To do. The fan rotation speed for supplying the air required to burn the fuel corresponding to the input amount is given in advance as a predetermined table in the storage means described later of the control unit 32.

Therefore, the controller 32 controls the air flow sensor 3
While monitoring the signal of 4, refer to this table,
The rotation speed of the fan 38 is determined, and the air necessary for burning the input fuel is sent. In addition, fan 3
The number of rotations of 8 may be detected by a rotation detecting unit using a Hall element or the like, a magnet, or the like, and the signal thereof may be given to the control unit 32.

Further, in the water heater 20, when the burner 33 disappears or the lift is detected by the frame rod 27, the proportional valve 24 is closed to stop the gas supply.

Further, the water heater 20 of this embodiment is provided with a pressure sensor 37 having one end connected to the combustion chamber in the case 21 and the other end connected to the exhaust passage 31. In this case, the pressure sensor 37 sends a signal based on the pressure difference between the exhaust passage 31 and the combustion chamber to the control unit 32. The connection location of the pressure sensor 37 is not limited to the combustion chamber and the exhaust passage 31. By connecting one end side and the other end side of the pressure sensor to the upstream side and the downstream side of the air supplied into the device, respectively, it is possible to select an appropriate location according to the type of the water heater and the like. . The detailed configuration and control method of the control unit 32 will be described later.

The control unit 32 includes a remote controller 3
9 is connected. Through the remote controller 39, the user can set the operation mode of the water heater 20. Further, as will be described later, a predetermined warning is displayed on the remote controller 39 from the control section 32.

As shown in FIG. 2, the control section 32 includes a flow sensor 26, a pressure sensor 37, and a frame rod (or a thermocouple or the like) as flame detecting means.
A hot water temperature (outflow) thermistor 25 is connected.

The flow sensor 26 and the water amount determination unit 41 are
The amount of water per unit time that passes through the water supply pipe 23 is detected, and this is transmitted to the comparison calculation unit 52. The pressure sensor 37 is connected to the differential pressure calculation unit 42, and in the present embodiment, detects the pressure difference between the exhaust passage 31 and the inside of the combustion chamber and transmits it to the comparison calculation unit 52. The flame detection means 27 is connected to the combustion state determination unit 43, converts the combustion state of the burner 33 at that time into a current (frame rod) or a voltage (thermocouple), and the comparison calculation unit 52, as described later. To give to.

The hot water temperature thermistor 25 is connected to the hot water temperature detecting unit 44, and compares the detection signal relating to the hot water temperature with a comparison calculation unit 52.
It is designed to be sent to. As described above, the operating state of the water heater 20 is monitored by each of these sensors or the calculation unit and the determination unit, and these collectively form a monitor unit.

The respective data sent from this monitor section are given to the comparison calculation section 52, and this comparison calculation section 52 is supplied.
Then, the comparison is performed with the data previously input to the memory unit 51, and the calculation of the difference or the change amount is performed. In this way, the memory unit 51 and the comparison operation unit 52 form a signal processing unit.

In the memory section 51 of this signal processing section, the relational data between the premixed air ratio and the flame rod current, which are obtained in advance by experiments or the like regarding the combustion of the burner 33, are inputted. This data is, for example, the data shown in FIG. 4, although it varies depending on the type of fuel gas. That is, according to FIG. 4, the flame rod current changes depending on the premixed air ratio of the fuel gas, and when the theoretical air amount (theoretical air ratio) is 1.0, the premixed air ratio is approximately 0.9.
Draw a bell-shaped curve that becomes maximum when.

This is because, as shown in FIG. 5, when the flame temperature changes depending on the premixed air ratio and the flame temperature is high,
This is because the flame rod current also becomes high due to the high ionic activity in the flame. When the flame detecting means 27 is composed of a thermocouple, the electromotive force generated in the thermocouple changes according to the flame temperature, and the detected voltage changes.

Therefore, the relationship data between the premixed air ratio and the flame rod current is experimentally obtained by changing the kind of the fuel gas, and is input to the memory section 51.
Here, when the water heater 20 includes, for example, a Bunsen burner, the data input to the memory unit 51 includes
The upper limit value A2 and the lower limit value A1 of the current shown by A in FIG. 4 are input, and the air amount corresponding to this range can be controlled.

When the water heater 20 is equipped with, for example, all primary burners, the data input to the memory unit 51 includes the upper limit value B2 and the lower limit value B of the current indicated by B in FIG.
1 is input so that the air amount corresponding to this range can be controlled. Furthermore, when the water heater 20 is, for example, a rich-lean combustion type water heater, it is provided with a rich-burn type burner and a lean-burn type burner. Therefore, as the data input to the memory unit 51, the current value corresponding to the lean burn burner indicated by C in FIG. 4 and the current value corresponding to the rich burn burner indicated by D are input. The air amount control corresponding to the current value is performed.

Further, the memory unit 51 includes a pressure sensor 3
Data for adjusting the amount of air (oxygen) to be supplied to the combustion chamber is previously obtained by an experiment in accordance with the differential pressure obtained from the detection signal of No. 7, and this is input. Specifically, if the differential pressure is large, the rotation speed of the fan 38 is increased and / or the opening degree of the damper 36 is increased to send a large amount of air (oxygen) to the combustion chamber. On the contrary, if the differential pressure is small, the rotation speed of the fan 38 is reduced and / or the opening degree of the damper 36 is decreased to limit the amount of air sent to the combustion chamber. Since such a value differs depending on the type of the burning appliance such as the water heater, individual data is input to the memory unit 51 according to these types.

The fan drive controller 53 and the damper controller 5
4 indicates the number of rotations of the fan 38 and the damper 36, as will be described later, in response to the calculation result of the comparison calculation unit 52.
The opening degree of is controlled individually or simultaneously. As a result, the amount of air supplied to the combustion chamber fluctuates, and the comparison calculation unit 52 and the fan drive control unit 5
3. The damper control unit 54 constitutes an air amount control unit.

Either one of the fan drive control unit 53 and the damper control unit 54 may be provided, but the fan 3
If data regarding the number of revolutions of 8 and the opening degree of the damper 36 is obtained in advance and is input to the memory unit 51, more accurate air amount control can be performed using the fan 38 and the damper 36.

It should be noted that the comparison calculation unit 52 is the gas amount control unit 5
5, alarm output unit 56, and water amount control unit 57, respectively. The gas amount control unit 55 is connected to the gas proportional valve 24. The alarm output unit 56 is connected to the remote controller 39 having the alarm display means 61. Water volume control unit 57
Is connected to the water amount control valve 19a.

In the water heater 20 as such a combustion device, when operating it, first turn on the power switch and open the water amount control valve 19a to pass water to the water supply pipe 23. This water amount is controlled by the control unit 32 by the water amount control valve 19
It is determined by adjusting the opening degree of a. When the flow sensor (water amount sensor) 26 provided in the pipe 29 detects that more than the working water amount has been passed, the fan 3
8 is rotated. The rotation of the fan is confirmed by the air flow sensor 34 and the like, the gas proportional valve 24 is opened, and the burner 33 is ignited by the igniter 28.

Next, the burner 3 is moved by the frame rod 27.
After confirming the ignition of No. 3, while monitoring with the temperature thermistor 25 until the water that has passed through the heat exchanger 30 becomes warm water of the set temperature, the gas input amount and the fan rotation speed are increased, and steady operation is started. The relationship data between the input amount of the fuel gas and the fan rotation speed is previously input to the memory unit 51 as data corresponding to a predetermined set temperature.

Next, as shown in the flow chart of FIG. 3, in the steady combustion state (ST11), the initial flow rate is detected by the flow sensor 26 and stored in the memory section 51 (STP1). The differential pressure calculation unit 42 receives the signal from the pressure sensor 37 and monitors it (ST2). When the differential pressure is equal to or higher than the set value, the wind is blowing outside the water heater 20, exhaust pressure is applied, or blockage or air leakage occurs somewhere in the passage of the air supplied by the fan 38. However, the exhaust of the combustion exhaust is not smooth, and there is a possibility that the air (oxygen) in the combustion chamber is insufficient. Further, even when oxygen is insufficient in the air, there arises a problem that the amount of oxygen required for combustion becomes insufficient.

Therefore, the signal from the flame detecting means composed of the flame rod 27 or the thermocouple is sent to the combustion state judging unit 4
The state of combustion is checked by monitoring at 3 (ST3). At this time, the signal from the combustion state determination unit 43 is compared with the comparison calculation unit 5
2, the data is compared with the data of FIG. 4 which is previously input to the memory unit 51, and the result is calculated. This comparison operation unit 5
At 2, it is determined whether or not the detection result is in the current range (temperature range) corresponding to A, B, C, D according to the burner type of the water heater 20 (ST3).

When the comparison calculation unit 52 determines that the current exceeds the specified current range, the air flow control unit controls the air flow (ST4). Specifically, when the water heater 20 is equipped with a Bunsen burner, the detected value sent from the flame detection means 27 via the combustion state determination unit 43 is
When the current value is higher than the current value data A2 stored in the memory section 51, the fan rotation speed is calculated according to the difference, and the fan drive control section 53 is calculated based on this calculation result. To increase the rotation speed of the fan 38. Incidentally, as described above, the opening degree of the fan damper 36 may be increased by the damper control section 54 separately or simultaneously therewith.

If a negative result is obtained in step 2,
The fan drive control unit 53 and the damper control unit 54 determine whether the rotation speed of the fan 38 is maximum (ST5).
If a negative result is obtained, the comparison calculation unit 52 causes the fan drive control unit 5 to operate according to the differential pressure detected by the pressure sensor 37.
3 or a command to the damper control unit 54 to increase the amount of air sent to the combustion chamber, the fan rotation speed is increased, or at the same time or separately, the opening degree of the damper 36 is increased.

When an affirmative result is obtained in ST5, the process proceeds to step 7 (ST7), and the comparison calculation unit 52 issues a command to the gas amount control unit 55 based on the calculation result to open the gas proportional valve 24. Reduce the degree. That is, the amount of gas is adjusted so that the fuel gas is supplied within a range in which good combustion can be performed, corresponding to the amount of air supplied to the combustion chamber.

Next, the flame temperature is checked by the same method as ST3 (ST8). If a negative result is obtained, the gas amount is adjusted again and readjusted so that good combustion is achieved.
If a positive result is obtained, the process proceeds to ST9, and the temperature of the hot water discharge at that time is confirmed by the temperature thermistor 25.

At this time, if the temperature is lower than the temperature set by the remote controller 39, the comparison calculation unit 52 performs calculation based on the data in the memory unit 51, and based on the result, the water amount control unit 5
The water amount control valve 19a is closed via 7 as much as the predetermined water amount. On the contrary, if the temperature is higher than the temperature set by the remote controller 39, the comparison calculation unit 52 performs a calculation based on the data of the memory unit 51, and based on the result, sets the water amount control valve 19a through the water amount control unit 57 to a predetermined value. Open as much water as needed.

If a positive result is obtained in ST9, ST
In step 11, the comparison calculation unit 52 determines that the values from the pressure sensor 37 and the differential pressure calculation unit 42 are the same as the above-mentioned differential pressure.
It is determined whether or not it is equal to or larger than the set value input in 1. If a negative result is obtained, the process returns to ST7.

If a positive result is obtained, the comparison operation unit 5
2 controls the water amount control valve 19a through the water amount control unit 57 to set the initial water amount (ST12). That is, this ST
After twelve, when the external pressure or the like is removed when there is a wind, it is necessary to take a measure to restore the original state without such a failure. Next, the hot water temperature thermistor 25 and the hot water temperature detection unit 44 determine whether or not the hot water discharged at the set initial water amount is the set temperature (ST13), and if a negative result is obtained, the comparison calculation unit 52 causes the memory unit 51 to operate. A signal is sent to the gas amount control unit 55 and / or the air amount control unit (the fan drive control unit 53, the damper control unit 54) based on the above data.

As a result, the amount of fuel gas input is adjusted, or the rotation speed of the fan 38 and the opening degree of the damper 36 are appropriately controlled to adjust the air volume. If a positive result is obtained in ST13, steady operation is continued unless the operation is stopped manually (ST17).

As described above, according to the water heater 20 and the combustion control method therefor of the present embodiment, as shown in FIG. 6, combustion is performed based on the detection signals of the pressure sensor 37 and the flame rod 27 as flame detecting means. You can check the amount of air (oxygen) supplied to the room. Accordingly, when the amount of air (air amount) sent out by the fan 38 is larger than the appropriate amount (F) (E), the fan rotation speed is reduced, and when it is small (G), the rotation speed of the fan 26 is reduced. To raise an appropriate amount of air. Simultaneously with or separately from this, the opening of the fan damper 36 is adjusted in the same manner.

Therefore, in the present embodiment, it is possible to quickly control the shortage or excess of the air amount required for combustion due to an abnormality such as an air leak or blockage of the water heater 20 or a wind outside the device. The present invention is not limited to the above embodiment. For example, as shown by the chain line in FIG. 1, the pressure sensor may be connected to the lower portion of the burner and the combustion chamber, respectively, and the pressure difference between them may be taken.

[0058]

As described above, according to the present invention, it is possible to provide a method for controlling a combustion device, which can appropriately supply the amount of air required by the burner for combustion in accordance with the amount of fuel input. it can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a water heater as a combustion device to which a preferred embodiment of the present invention is applied.

FIG. 2 is a block diagram showing a control block of the water heater of FIG.

FIG. 3 is a flowchart showing the operation of the first exemplary embodiment of the present invention.

FIG. 4 is a diagram showing a difference in flame rod current depending on an air ratio of a premixed gas.

FIG. 5 is a graph showing a difference in flame temperature depending on an air ratio of premixed gas.

FIG. 6 is an explanatory diagram showing a state of air volume control according to the embodiment.

FIG. 7 is a schematic configuration diagram showing an example of a conventional combustion device.

[Explanation of symbols]

 20 Water Heater (Combustion Device) 24 Gas Proportional Valve 25 Hot Water Temperature Thermistor 26 Flow Sensor 27 Frame Rod 32 Controller 36 Damper 37 Pressure Sensor 38 Fan 39 Remote Controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoto Tominaga 3-4 Fukamidai, Yamato-shi, Kanagawa Inside Gaster Co., Ltd.

Claims (4)

[Claims] 1. A combustion device in which air is supplied to a combustion chamber by a fan and combustion exhaust gas is discharged through an exhaust passage, wherein one end of an air passage introduced into the device by the fan is used. Is provided on the upstream side, and the other end is connected to the downstream side, and a pressure sensor is provided. 2. A combustion control method for a combustion device, wherein air is supplied to a combustion chamber by a fan, and the number of revolutions of the fan is controlled to adjust the amount of air. A pressure sensor was installed in the passage, and based on the value detected by this sensor, the amount of air supplied to the device was controlled, and the combustion flame temperature of the burner was detected to respond to a preset good combustion state. A combustion control method for a combustion device, wherein when the temperature exceeds the temperature range, the amount of air supplied to the device is further controlled to bring about a good combustion state. 3. A combustion control method for a combustion device, wherein air is supplied to a combustion chamber by a fan, and the rotational speed of the fan is controlled to adjust the amount of air. A pressure sensor was installed in the passage, and based on the value detected by this sensor, the amount of air supplied to the device was controlled, and the combustion flame temperature of the burner was detected to respond to a preset good combustion state. When the temperature exceeds the temperature range, the number of revolutions of the fan is controlled, and / or a damper for opening / closing a passage of air supplied by the fan is opened / closed to achieve a good combustion state. Combustion control method. . 4. The supply amount of fuel gas is reduced and the supply amount of water to be heated in the device is reduced when the fan rotation speed is maximum and / or the damper opening is maximum. The combustion control method for a combustion apparatus according to claim 3, wherein the combustion control method is performed.