JP2006292285A - Heat equipment for adjusting combustion air supply quantity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide heat equipment, capable of performing appropriate combustion by correcting an amount of air supply in conformation to change of the ambient temperature. <P>SOLUTION: This heat equipment comprises a combustion device 2 performing combustion by injecting fuel from a fuel nozzle 4 and injecting combustion air from a blower 5 through an air injection port 6; and a combustion control device 10 controlling the amount of fuel supply and the amount of combustion air supply to be supplied to the combustion device 2 so that the burning capacity can be changed stepwise by increasing and decreasing the amount of fuel supply and the amount of air supply. This equipment further comprises a differential pressure detection device 3 detecting a detected differential pressure Ps that is a differential pressure between a combustion air supply pressure on the upstream side from the air injection port 6 and a furnace pressure on the downstream side from the air injection port and an air supply temperature detector 9 detecting a detected temperature Ta that is a combustion air supply temperature on the upstream side from the air injection port 6. A target differential pressure value necessary for determination of an appropriate amount of combustion air supply is calculated based on the value of the detected temperature Ta, and the quantity of combustion air supply is corrected so that the detected differential pressure Pa gets close to the target differential pressure value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal device that changes a combustion amount by adjusting a fuel supply amount and a combustion air supply amount, and relates to a thermal device that adjusts a combustion air supply amount according to a combustion air supply temperature. Is.

Thermal equipment that changes the combustion amount by increasing or decreasing the fuel supply amount and the combustion air supply amount is widely used. When changing the combustion amount at three positions of high combustion, low combustion, and stop, set the high combustion fuel supply amount and high combustion air supply amount, and the low combustion fuel supply amount and low combustion air supply amount. In addition, the amount of combustion is changed by switching the magnitude of the fuel supply amount and the magnitude of the air supply amount.
In the case of high combustion, the fuel supply amount and the combustion air supply amount are increased, and in the case of low combustion, the fuel supply amount and the combustion air supply amount are decreased, and the appropriate amount is supplied for each combustion amount. By doing so, the ratio of fuel and air is set to be appropriate.

  However, in actuality, the fuel / air ratio has shifted due to changes in temperature and the like. That is, in the summer when the temperature rises, the air density decreases due to air expansion. Conversely, in the winter when the temperature decreases, the air density increases due to air contraction. Therefore, in summer, the amount of oxygen contained in a certain volume is small even if the amount of combustion air sent from the blower is constant, so that the amount of air (oxygen amount) becomes insufficient. Similarly, in winter, the amount of oxygen contained in a certain volume increases, and thus the amount of air (oxygen amount) is excessive.

  In Japanese Patent Application No. 2003-362507, the combustion air supply amount is adjusted based on the differential pressure ΔP between the combustion air supply pressure P1 upstream of the air injection port and the furnace pressure P2 downstream of the air injection port. There is a description of what to do. However, even if the air volume is adjusted so that the differential pressure is within the reference range, there is a problem that the air volume is insufficient in the summer when the air density is low, and the air volume is excessive in the winter when the air density is high. It sometimes occurred.

Japanese Patent Application No. 2003-362507

  The problem to be solved by the present invention is to provide a thermal apparatus capable of correcting the air supply amount in response to a change in temperature and performing proper combustion.

According to the first aspect of the present invention, the fuel sent from the fuel supply line is injected from the fuel nozzle, and the combustion air sent from the blower is jetted from the air injection port, whereby the fuel and the combustion air are supplied. Combustion device that performs combustion by mixing, and combustion control device that controls the fuel supply amount and combustion air supply amount supplied to the combustion device, the fuel supply amount and combustion air supply amount are stepwise In the thermal equipment that enables the stepwise change of the combustion amount by increasing or decreasing the fuel supply amount and the combustion air supply amount,
A differential pressure detection device that detects a detected differential pressure (Ps) that is a differential pressure between the combustion air supply pressure upstream of the air injection port and the pressure inside the furnace downstream of the air injection port; and an upstream side of the air injection port A supply air temperature detection device that detects a detection temperature (Ta) that is a combustion air supply temperature is provided, and an appropriate combustion air supply is based on the value of the detection temperature (Ta) detected by the supply air temperature detection device. The target differential pressure value necessary for determining the amount is calculated, and the supply amount of combustion air is corrected so that the detected differential pressure (Pa) detected by the differential pressure detector approaches the target differential pressure value. It is a thermal device that adjusts the combustion air supply amount.

に基づき目標差圧値の算出を行うことを特徴とする。 According to a second aspect of the present invention, in the thermal apparatus that adjusts the combustion air supply amount, the reference temperature (Tr) that is the supply temperature of the reference combustion air and the supply of the reference combustion air A reference differential pressure (Pr) that is a differential pressure value between the pressure and the furnace pressure is set in advance,

The target differential pressure value is calculated based on the above.

  According to a third aspect of the present invention, when the combustion amount is switched between high combustion and low combustion in the thermal device that adjusts the combustion air supply amount, the change of the combustion air supply amount is started first. A thermal device that is designed to change the fuel supply amount in the middle of changing the combustion air supply amount, and when the combustion air supply amount is corrected based on the target differential pressure value, The timing of changing the fuel supply amount is corrected when the combustion amount is changed in conjunction with the correction of the air supply amount.

  According to a fourth aspect of the present invention, in the thermal apparatus that adjusts the combustion air supply amount, a predetermined correctable width is set for correcting the combustion air, and the limit value of the correctable width is reached. However, if the detected differential pressure (Ps) does not reach the target differential pressure value, it is determined that an abnormality has occurred in the device.

  According to a fifth aspect of the present invention, in the thermal apparatus that adjusts the combustion air supply amount, the detected differential pressure (Ps) detected by the differential pressure detector is an abnormal value that deviates from a predetermined range. In this case, it is determined that the differential pressure detecting device is abnormal, and correction of the combustion air supply amount based on the differential pressure is stopped.

  By practicing the present invention, even if the air density changes due to changes in the air temperature, it is possible to correct combustion by correcting the amount of combustion air supplied and adjusting the oxygen amount. Further, since the timing for switching the increase / decrease of the fuel supply amount is changed in conjunction with the correction of the combustion air supply amount, stable combustion can be performed even when the combustion amount is likely to become unstable.

  In addition, when an abnormality occurs in the differential pressure detection device and a correct value cannot be detected, the combustion air supply amount is adjusted based on an incorrect value. When the differential pressure detecting device is abnormal, the combustion abnormality is prevented by stopping the correction of the combustion air supply amount based on the differential pressure. Further, if the target differential pressure value is not reached even when the combustion air supply amount is corrected to the limit value, it is determined that an abnormality has occurred, so an abnormality such as a blockage due to soot can be detected.

  FIG. 1 is a block diagram showing an outline of a boiler embodying the present invention, and FIG. 2 is a flowchart for correcting the amount of combustion air supplied to the boiler embodying the present invention. The boiler 1 is provided with a combustion device 2 and a blower 5 at the top, and the combustion device 2 is provided with a fuel nozzle 4 and an air injection port 6. A wind box 11 is provided between the blower 5 and the combustion device 2, and air from the blower 5 is directed to the combustion device 2 through the wind box 11. The fuel nozzle 4 injects the fuel sent through the fuel supply line 15 into the furnace 13, and the air injection port 6 injects the air sent through the wind box 11 into the furnace 13. The fuel and the combustion air are mixed and burned.

  A supply pressure detecting device 7 for detecting the supply pressure of combustion air (wind box pressure) is provided in the wind box 11, and an in-furnace pressure detecting device 8 is provided in the furnace 13. The supply pressure detection device 7 and the in-furnace pressure detection device 8 are a part of the differential pressure detection device 3, and the differential pressure detection device 3 subtracts the in-furnace pressure from the combustion air supply pressure to detect the differential pressure (detection differential pressure). (Ps)) is detected. The detected detected differential pressure (Ps) is output to the combustion control device 10. The wind box 11 is also provided with a supply air temperature detection device 9 that detects the supply temperature (detection temperature (Ta)) of combustion air, and the detected temperature (Ta) detected by the supply air temperature detection device 9 is also combustion controlled. The data is output to the device 10.

  The combustion control device 10 controls combustion such as adjustment of the fuel supply amount and the combustion air supply amount, and controls the fuel supply amount control device 14 provided in the fuel supply line 15 and the operation of the blower 5. The inverter device 12 which is a blower rotation speed control device is also connected. When the boiler 1 is operated, the combustion control device 10 controls the fuel supply amount control device 14 and the inverter device 12.

  In the case of a boiler that changes the combustion amount at three positions of high combustion, low combustion, and stop, the combustion control device 10 uses a high combustion fuel supply amount and a high combustion air supply amount, and a low combustion fuel supply amount and a low combustion purpose. An air supply amount is set, and the combustion amount is changed by switching between a fuel supply amount and an air supply amount. The boiler operation control increases the amount of steam generated by increasing the combustion amount from low combustion to high combustion when the pressure value of the steam held during low combustion with a small amount of steam decreases below the set value. When the steam pressure value rises to a set value or more during high combustion with a large amount of steam generation, control is performed to reduce the combustion amount from high combustion to low combustion.

  Since the combustion air supply amount adjusts the combustion air supply amount by changing the rotation speed of the blower by increasing or decreasing the frequency output from the inverter device 12, the high combustion frequency and the low combustion frequency Is set in advance. In addition, when the combustion amount is switched between high combustion and low combustion, a frequency of timing for changing the fuel supply amount is set. The setting value for switching the combustion amount is the value that sets the timing for increasing the fuel supply amount when the combustion amount is switched from low combustion to high combustion, when the combustion amount is switched from high combustion to low combustion. It is set to a value lower than the set value of the timing for reducing the supply amount.

  The frequency is set as an initial value, for example, the frequency for high combustion is 55 Hz, the frequency for low combustion is 30 Hz, and the frequency for increasing the fuel supply amount when changing the combustion amount from low combustion to high combustion is 35 Hz, high The frequency for reducing the fuel supply amount when changing the combustion amount from combustion to low combustion is set to 50 Hz.

  When shifting from low combustion to high combustion, the combustion control device 10 first outputs a command to the inverter device 12 to increase the output frequency from the low combustion frequency to the high combustion frequency. Increase the output frequency. The combustion control device 10 detects the frequency output from the inverter device 12, and when the output frequency from the inverter device 12 reaches 35Hz, which is a set value for changing the fuel supply amount from low combustion to high combustion, combustion occurs. The control device 10 outputs a command for increasing the fuel supply amount to the fuel supply amount control device 14. Similarly, when shifting from high combustion to low combustion, the combustion control device 10 first outputs a command to the inverter device 12 to reduce the output frequency from the high combustion frequency to the low combustion frequency. Reduce the output frequency of the device 12. When the output frequency of the inverter device 12 reaches 50 Hz, which is a set value for changing the fuel supply amount from high combustion to low combustion, a command to reduce the fuel supply amount is output to the fuel supply amount control device 14.

  The frequency setting does not need to be changed if the combustion air supply temperature is constant, but the combustion air supply temperature changes depending on the season, and the appropriate combustion air supply amount changes. Correct. The combustion control device 10 calculates a target differential pressure value based on the detected temperature (Ta) detected by the supply air temperature detecting device 9, and the detected differential pressure (Ps) detected by the differential pressure detecting device 3 is the target. The combustion air supply amount is adjusted so as to approach the differential pressure value.

ボイラ毎の設置環境には差があるため、ボイラ設置時に燃焼調整を行い、ボイラごとに適切となる燃焼用空気供給量を設定するようにしている。そのため、基準温度（Ｔｒ）は燃焼調整時における燃焼用空気の供給温度、基準差圧（Ｐｒ）は燃焼調整時における燃焼用空気の供給圧力と炉内圧力の差圧とし、燃焼調整時点で各基準値を燃焼制御装置１０に入力する。基準差圧（Ｐｒ）と基準温度（Ｔｒ）は、高燃焼用と低燃焼用でそれぞれ設定しておき、高燃焼の場合は高燃焼用基準差圧（ＰｒＨ）と高燃焼用基準温度（ＴｒＨ）、低燃焼の場合は低燃焼用基準差圧（ＰｒＬ）と低燃焼用基準温度（ＴｒＬ）としておく。 In calculating the target differential pressure value, the temperature of the reference combustion air is set as the reference temperature (Tr), and the reference pressure (Pr) is set as the differential pressure between the supply pressure of the reference combustion air and the pressure in the furnace. The target differential pressure value is determined based on the following equation.

Since there is a difference in the installation environment for each boiler, combustion adjustment is performed at the time of boiler installation, and an appropriate combustion air supply amount is set for each boiler. Therefore, the reference temperature (Tr) is the supply temperature of combustion air at the time of combustion adjustment, and the reference differential pressure (Pr) is the differential pressure between the supply pressure of combustion air and the pressure in the furnace at the time of combustion adjustment. The reference value is input to the combustion control device 10. The reference differential pressure (Pr) and the reference temperature (Tr) are set for high combustion and low combustion, respectively. In the case of high combustion, the high combustion reference differential pressure (PrH) and the high combustion reference temperature (TrH In the case of low combustion, a low combustion reference differential pressure (PrL) and a low combustion reference temperature (TrL) are set.

  Since the volume of the gas at a constant pressure is proportional to the absolute temperature, and the differential pressure is proportional to the square of the gas volume to be supplied, the detected temperature value converted to the absolute temperature is divided by the reference temperature value converted to the absolute temperature, and the value is divided. By multiplying the squared value by the reference differential pressure (Pr), the target differential pressure value is obtained. If the combustion air supply amount is adjusted so as to be the target differential pressure value, the necessary oxygen amount can be supplied even if the air density changes due to changes in the temperature. The combustion control device 10 uses the detected temperature (Ta) detected by the supply air temperature detection device 9 and the preset reference differential pressure (Pr) and reference temperature (Tr) as the target differential pressure value calculation formula. By substituting, the target differential pressure value is calculated.

  Whether the combustion control device 10 needs to correct the combustion air supply amount by comparing the detected differential pressure (Ps) detected by the differential pressure detection device 3 with the target differential pressure value calculated from the calculation formula. Determine whether or not. In the combustion control device 10, when the detected differential pressure (Ps) is 0.1 kPa or more lower than the target differential pressure value, control is performed to increase the output frequency from the inverter device 12, and the detected differential pressure (Ps) and the target differential pressure are controlled. Increase the combustion air supply to eliminate the difference. On the other hand, when the detected differential pressure (Ps) is higher than the target differential pressure value by 0.1 kPa or more, control is performed to reduce the output frequency from the inverter device 12, and the difference between the detected differential pressure (Ps) and the target differential pressure value is performed. The amount of combustion air supplied is reduced so as to eliminate the problem.

For example, during high combustion, high combustion reference differential pressure (PrH) = 4.0 kPa, high combustion reference temperature (TrH) = 20 ° C., detection temperature (Ta) = 30 ° C., detection differential pressure (Ps) = 4 Suppose that it was 0.0kPa. Substituting each of the above values into the target differential pressure value calculation formula yields target differential pressure value = 4.0 × ((30 + 273 / (20 + 273)) ² , and when calculated, the target differential pressure value = 4.28 kPa. The detected differential pressure (Ps), which is the differential pressure, is 4.0 kPa, which is 0.28 kPa lower than the target differential pressure value of 4.28 kPa.

  In this case, since the temperature is higher than that at the time of combustion adjustment and the amount of oxygen is insufficient unless the amount of combustion air is increased, the combustion control device 10 performs control to increase the output frequency of the inverter device 12. I do. If the output frequency of the inverter device 12 is increased, the rotational speed of the blower 5 is increased and the amount of combustion air to be supplied is increased, so that the amount of supplied oxygen is increased. Further, if the supply amount of combustion air is increased, the pressure in the wind box 11 also increases, so the differential pressure (detected differential pressure (Ps)) between the wind box 11 and the furnace 13 increases.

  The output frequency by the inverter device 12 increases in increments of 0.1 Hz, and the differential pressure is detected with the output frequency increased. If the detected differential pressure (Ps) detected by the differential pressure detecting device 3 does not reach the target differential pressure value, the output frequency from the inverter device 12 is further increased and the output of the blower is output until the target differential pressure value is reached. Increase the frequency. It should be noted that the detected differential pressure (Ps) and the target differential pressure value do not have to coincide completely, and if the difference between the detected differential pressure (Ps) and the target differential pressure value is smaller than a certain amount (eg, less than 0.1 kPa). You may judge that both became equal.

  In this embodiment, since the initial set frequency of high combustion is 55 Hz, the combustion control device 10 first corrects the frequency output from the inverter device 12 from 55 Hz to 55.1 Hz, and in this state, the differential pressure detection device 3 The detected differential pressure (Ps) is detected. When the frequency of the inverter device 12 is corrected to 55.1 Hz, the detected differential pressure (Ps) increases because the air supply amount increases, and whether or not the detected differential pressure (Ps) has reached the target differential pressure value in this state. Determine. If the detected differential pressure (Ps) increases by 0.05 KPa by increasing the frequency by 0.1 Hz, the detected differential pressure (Ps) at this time becomes 4.05 KPa, but the detected differential pressure (Ps) is still the target. Since it is lower than the differential pressure value, the frequency of the inverter device 12 is increased again. The detection of the differential pressure and the frequency change are repeated at intervals of about 1 second until the detected differential pressure (Ps) reaches the target differential pressure value.

  As the temperature rises, the air expands and the density decreases, so the oxygen content decreases if the pressure and volume are the same. When the rotational speed of the blower is constant, the volume of combustion air sent by the blower is constant, so that the amount of oxygen is insufficient by the amount that the air density is reduced due to the rise in temperature. When the output frequency of the inverter device 12 is increased, the rotational speed of the blower 5 is increased, so that the amount of combustion air supplied from the blower 5 can be increased. Even if the oxygen content is decreased due to a decrease in density, an appropriate amount of oxygen can be supplied and an appropriate combustion can be performed by increasing the oxygen amount by increasing the combustion air supply amount.

  Assuming that the detected differential pressure (Ps) becomes substantially equal to the target differential pressure value by increasing the high combustion frequency by 0.5 Hz and correcting it to 55.5 Hz, the combustion control device 10 sets the output frequency of the inverter device 12. End the operation to be changed. Further, in the combustion control device 10, when changing from high combustion to low combustion, the set value for changing the fuel supply amount is also corrected to increase by the same 0.5 Hz. When changing from high combustion to low combustion, the fuel supply amount is reduced by a certain amount lower than the combustion air supply amount during high combustion, so the combustion air supply amount during high combustion was changed. In this case, if the timing for reducing the fuel supply amount is not changed when changing from high combustion to low combustion, the balance of the air-fuel ratio may be lost when the combustion amount is changed. Therefore, the set value for changing from the high combustion fuel supply amount to the low combustion fuel supply amount is also increased by 0.5 Hz to 50.5 Hz. In this state, when the combustion transition from high combustion to low combustion is performed by increasing the steam pressure value, the combustion control device 10 first outputs a command to change the output frequency of the inverter device 12 from 55.5 Hz to 30 Hz. The combustion control device 10 detects the output frequency from the inverter device 12 and outputs a command to the fuel supply amount control device 14 to decrease the fuel supply amount when detecting that the output frequency has reached 50.5 Hz. Control.

The same applies to the case of low combustion. For example, low combustion reference differential pressure (PrL) = 1.0 kPa, low combustion reference temperature (TrL) = 20 ° C., detection temperature (Ta) = 30 ° C., detection differential pressure (Ps ) = 1.0 kPa. If each of the above values is substituted into the target differential pressure value calculation formula, the target differential pressure value = 1.0 kPa × ((30 + 273 / (20 + 273)) ² , and when calculated, the target differential pressure value = 1.07 kPa. The pressure (Ps) is 1.0 kPa, which is 0.07 kPa lower than the target differential pressure value of 1.07 kPa. Therefore, strictly speaking, the proportion of oxygen is reduced, but the target differential pressure value and the detected differential pressure ( If the difference in Ps) is less than 0.1 kPa, it can be determined that the air-fuel ratio is substantially appropriate. In this case, correction of the combustion air supply amount is unnecessary.

  The timing for increasing the fuel supply amount when changing from low combustion to high combustion is a certain amount higher than the combustion air supply amount during low combustion, so the combustion air supply amount during low combustion is changed. In this case, if the timing for increasing the fuel supply amount is not changed when changing from low combustion to high combustion, the air-fuel ratio balance may be lost when the combustion amount is changed. Therefore, when the low combustion frequency is changed, the setting value for increasing the fuel supply amount is changed by the same width when changing from low combustion to high combustion. Is not changed, the set value that determines the timing for increasing the fuel supply amount is not changed.

  In addition, a variable range of the inverter frequency is set in the combustion control device 10, and an abnormality occurs when the detected differential pressure (Ps) does not reach the target differential pressure value even when the limit of the variable range is reached. Judgment is made. The maximum value and minimum value of the low combustion frequency and the maximum value and minimum value of the high combustion frequency are set. Even if the frequency reaches the limit value in each combustion state, the detected differential pressure (Ps) is the target difference. When the pressure value is not reached, an inspection display is output. When the fluctuation range is ± 5 Hz, the frequency increases or decreases from the initial value to ± 5 Hz, but when it reaches ± 5 Hz, no further frequency change is performed. Even if the frequency of the inverter device 12 is changed to the limit of the fluctuation range, the detected differential pressure (Ps) does not reach the target differential pressure value. This means that the pressure in the furnace is due to the combustion gas passage being blocked by the soot adhesion. In this case, the abnormality is notified by blinking the inspection indicator light.

  A detection width is also set for the detected differential pressure (Ps), and the pressure difference detected by the supply pressure detection device 7 and the furnace pressure detection device 8 deviates from the detection width (continues for a certain period of time to prevent noise) If the error occurs, it is determined that an abnormality has occurred. A detection range that can be determined to be normal at the time of both low combustion and high combustion is set, and if the value of the detected differential pressure (Ps) deviates from the detection range in each combustion state, the supply pressure detection device 7 or the pressure in the furnace It can be considered that an abnormality has occurred in any of the detection devices 8. If the supply amount of combustion air is adjusted based on an erroneous detection value by the abnormal differential pressure detection device 3, abnormal combustion will be caused. Therefore, when the differential pressure detection device 3 is abnormal, combustion based on the differential pressure is caused. By preventing the change in the supply air amount, the combustion state is prevented from becoming abnormal. When an abnormality occurs in the supply pressure detection device 7 or the furnace pressure detection device 8 and a correct differential pressure cannot be detected, the correction of the combustion air supply amount based on the differential pressure is stopped, but the operation of the boiler is also stopped. Since it is not necessary, the boiler is operated with the combustion air supply amount set first. In this case, since it is the same as a normal boiler that does not perform air volume correction, an abnormality is notified by blinking an inspection indicator light or the like.

Configuration diagram of a boiler implementing the present invention Flowchart for correcting the combustion air supply amount of the present invention

Explanation of symbols

1 boiler
2 Combustion device
3 Differential pressure detector
4 Fuel nozzle
5 Blower
6 Air injection port
7 Supply pressure detection device 8 In-furnace pressure detection device 9 Supply air temperature detection device 10 Combustion control device 11 Wind box 12 Inverter device 13 In-furnace 14 Fuel supply amount control device 15 Fuel supply line

Claims (5)

A combustion device that injects fuel sent from a fuel supply line from a fuel nozzle and mixes fuel and combustion air by injecting combustion air sent from a blower from an air injection port; And a combustion control device for controlling the fuel supply amount and the combustion air supply amount supplied to the combustion device. The fuel control device sets the fuel supply amount and the combustion air supply amount in stages, and the fuel supply amount. In the thermal equipment that enables a gradual change in the combustion amount by increasing or decreasing the combustion air supply amount,
A differential pressure detection device that detects a detected differential pressure (Ps) that is a differential pressure between the combustion air supply pressure upstream of the air injection port and the pressure inside the furnace downstream of the air injection port; and an upstream side of the air injection port A supply air temperature detection device that detects a detection temperature (Ta) that is a combustion air supply temperature is provided, and an appropriate combustion air supply is based on the value of the detection temperature (Ta) detected by the supply air temperature detection device. The target differential pressure value necessary for determining the amount is calculated, and the supply amount of combustion air is corrected so that the detected differential pressure (Pa) detected by the differential pressure detector approaches the target differential pressure value. A thermal device that adjusts the combustion air supply. 2. A thermal apparatus for adjusting a combustion air supply amount according to claim 1, wherein a reference temperature (Tr) which is a supply temperature of combustion air serving as a reference, a supply pressure of combustion air serving as a reference, and a furnace pressure A reference differential pressure (Pr) that is a differential pressure value of

A thermal apparatus for adjusting the supply amount of combustion air, wherein the target differential pressure value is calculated based on the above. In the thermal apparatus for adjusting the combustion air supply amount according to claim 1 or 2, when the combustion amount is switched between high combustion and low combustion, the change of the combustion air supply amount is started first, A thermal device that is designed to change the fuel supply amount in the middle of changing the air supply amount, and when the combustion air supply amount is corrected based on the target differential pressure value, the combustion air supply amount A thermal apparatus for adjusting the combustion air supply amount, wherein the timing for changing the fuel supply amount is changed when the combustion amount is changed in conjunction with the correction of the combustion. In the thermal apparatus for adjusting the combustion air supply amount according to any one of claims 1 to 3, a predetermined correctable width is set for correction of the combustion air, and the limit value of the correctable width is reached. However, if the detected differential pressure (Ps) does not reach the target differential pressure value, it is determined that an abnormality has occurred in the device. . 5. The thermal apparatus for adjusting the combustion air supply amount according to any one of claims 1 to 4, wherein the detected differential pressure (Ps) detected by the differential pressure detection device is an abnormal value that falls outside a predetermined range. In this case, it is determined that the differential pressure detection device is abnormal, and correction of the combustion air supply amount based on the differential pressure is stopped.

Images