JPH11257657A - Combustion control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion control device to enable identification of the ventilating status of a fan with as high accuracy as possible while reducing a cost thereof. SOLUTION: A combustion control device comprises a revolution detection means 4a for detecting the number of revolutions of a fan 4 to ventilate combustion air to a burner 3, and a feedback control is performed on the basis of information detected by the revolution detection means 4a, wherein driving power supply quantity is adjusted to set the number at revolutions of the fan 4 to the number of target revolutions for ignition in the ignition mode. In the normal combustion mode, a control means H is provided to adjust driving power supply quantity so as to control the number of revolutions of the fan 4 to the number of target revolutions for normal combustion. In the ignition mode, the control means H obtains an integrated value of the driving power supply quantity which is adjusted before the number of revolutions of the fan 4 is controlled from start of driving the fan 4 to the number of target revolutions for ignition, thereby identifying the fan 4 ventilation status based on the integrated value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan for blowing combustion air through a burner, rotation speed detecting means for detecting the rotation speed of the fan, and adjusting the amount of driving power supplied to the fan. Control means for controlling the number of revolutions, wherein the control means sets the fan to the target number of revolutions for ignition in an ignition mode in which the burner is ignited by feedback control based on information detected by the number of revolutions detection means. And a combustion control device configured to control the drive power supply amount so as to achieve a target rotation speed for normal combustion in the normal combustion mode after the ignition mode. About.

[0002]

2. Description of the Related Art In the above-described combustion control device, an air flow sensor or the like for detecting an air flow is provided in a ventilation path of combustion air, and based on detection information of the air flow sensor,
A device that determines a ventilation state of a fan is known. Further, in an ignition mode for igniting a burner, in a state in which a drive power supply amount is adjusted so that the fan reaches a target rotation speed for ignition, a ventilation state of the fan is determined based on a drive power value at that time. Is also known.

[0003]

However, the provision of the air flow sensor has a disadvantage that the cost is increased by the amount of the air flow sensor. Since the determination is made based on the driving power value in the above, it is not always possible to make a precise determination.In particular, since the driving power value is unstable in the initial stage of driving the fan, the determination of the ventilation state of the fan can be accurately performed. There were things I couldn't do.

The present invention has been made in view of such a point, and an object of the present invention is to provide a combustion control device capable of judging a ventilation state of a fan as accurately as possible while reducing costs. It is in.

[0005]

In order to achieve this object, according to the first aspect of the present invention, in an ignition mode, a control means controls a start of driving of a fan to a target rotational speed for ignition. The integrated value of the drive power supply amount adjusted up to this point is obtained, and the ventilation state of the fan is determined based on the integrated value. In other words, there is no need to provide an air flow sensor or the like, and it is not a single drive power value at a certain moment but a drive power supply adjusted from the start of driving of the fan to the control of the target number of revolutions for ignition, while reducing cost. Since the ventilation state is determined based on the integrated value of the amount, it is possible to determine the ventilation state more accurately than in the above-described method based on the driving power value.

According to the second aspect of the present invention, the control means sets the ventilation state of the fan as a ventilation abnormal state where the integrated value is equal to or less than the abnormality determination value, and the integrated value is set to a value larger than the abnormality determination value. Since the ventilation normal state that is equal to or greater than the normal determination value, and the ventilation intermediate state in which the integrated value is less than the normal determination value and greater than the abnormality determination value, it is configured to be divided into three stages, and for example, Compared with the case of distinguishing between two stages of the abnormal ventilation state and the normal ventilation state, the ventilation state can be determined with higher accuracy, and the subsequent processing according to the ventilation state can be executed accurately. It becomes possible.

In other words, in the case of discriminating in two stages, even when it is difficult to determine whether the ventilation is abnormal or the ventilation is normal, it is necessary to determine one of them. Therefore, for example, when giving priority to normal ventilation, if the integrated value is less than the normal determination value, even if the integrated value is close to the normal determination value, it must be determined that ventilation is abnormal, and conversely, The same applies when an abnormality is prioritized. In this regard, the above-mentioned intermediate ventilation state is discriminated into three stages, and in the case of the intermediate ventilation state, another method, for example, of the integrated value of the driving power supply amount, is set to the target rotation speed for ignition. Accurate discrimination of the ventilation state is possible by taking into account the discrimination by other methods, such as discriminating with emphasis on the integrated value on the near side.

According to the third aspect of the present invention, when the integrated value is equal to or less than the intermediate judgment value set between the abnormality judgment value and the normal judgment value in the intermediate ventilation state, the control means sets the quasi-abnormal state. When the integrated value is larger than the intermediate determination value, the quasi-normal state is determined. In other words, the normal ventilation state where the ventilation state is definitely normal and the ventilation abnormal state where the ventilation state is definitely abnormal are determined, and the intermediate determination value is determined in the ventilation intermediate state where the ventilation state is normal or abnormal or uncertain. Is appropriately set to determine the quasi-normal state on the normal ventilation side and the quasi-abnormal state on the abnormal ventilation side, and as a result, the ventilation state is classified into four stages. Can be performed more accurately,
Even in the intermediate ventilation state where the ventilation state is uncertain, the subsequent processing can be executed appropriately.

According to the fourth aspect of the present invention, in the quasi-abnormal state, if the drive power value when the fan is controlled to the target ignition speed is smaller than the set value for abnormality determination, the control means may be abnormal. Is configured to be determined.
In other words, even in the quasi-abnormal state on the ventilation abnormal side, the abnormality of the ventilation state can be determined based on the driving power value at the ignition target rotation speed instead of the integrated value of the driving power supply amount. Can be more reliably determined, and subsequent processing can be executed in a manner that reliably copes with the abnormality in the ventilation state.

According to the fifth aspect of the present invention, when the control means detects an abnormal ventilation state, and when the control means determines an abnormality based on the driving power value in the quasi-abnormal state, the ignition processing for igniting the burner is performed. Is stopped, and in the normal ventilation state, the quasi-normal state, and the quasi-abnormal state, when the abnormality is not determined based on the drive power value, the ignition means is operated to perform an ignition process of igniting the burner. I have. Therefore, when it is determined that the ventilation state is abnormal based on the ventilation state determined with high accuracy, the ignition process for the burner is stopped and, for example, an abnormality in the ventilation state such as a supply / exhaust blockage of combustion air. Thereby, it is also possible to prevent the generation of so-called explosion ignition, in which raw gas remains in the combustion chamber of the burner and generates a large ignition sound when the burner is ignited. In other words, since an appropriate ignition process corresponding to the ventilation state can be executed, it is possible to prevent explosion ignition or the like without unnecessarily stopping the ignition process.

According to the present invention, if the flame detecting means for detecting the combustion state of the burner does not detect the ignition of the burner during the execution of the ignition processing, the control means ignites the fan at that time. It is configured to determine whether the drive power value at the time of controlling to the target rotation speed is smaller than a set value for abnormality determination, and if it is smaller, it is determined that ventilation is abnormal, and the ignition process is stopped. I have. In other words, if there is misfiring due to an ignition processing error, the ventilation state is determined and if ventilation is abnormal, the subsequent ignition processing is stopped, and the occurrence of abnormalities during ignition processing such as explosion ignition due to abnormal ventilation conditions is ensured. Can be prevented.

According to a seventh aspect of the present invention, the control means is configured to stop the combustion of the burner when the flame detecting means detecting the ignition of the burner determines that the combustion state of the burner is not normal. I have. That is, even if ignition of the burner is detected, the abnormality of the combustion state of the burner can be determined and the combustion of the burner can be stopped.
The burner can be burned in a stable combustion state.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which a combustion control device according to the present invention is applied to a hot water supply device will be described with reference to the drawings. As shown in FIG. 1, the hot water supply apparatus includes a hot water supply section K for heating supplied water and supplying hot water to hot water tap 7, a control section H as control means for controlling the operation of hot water supply section K, and a control section H. H is provided with a remote control operation unit R for instructing operation information to H.

The hot water supply unit K includes a heat exchanger 2 for heating water, a gas combustion type burner 3 for heating the heat exchanger 2, and combustion air from the upstream side to the burner 3 in the combustion chamber 1. A fan 4 that allows ventilation and changes the ventilation volume
A rotation speed sensor 4a as rotation speed detecting means for detecting the rotation speed of the fan 4 is provided.
For example, an intake channel 5 to which water is supplied from a household water supply,
Hot water taps 6 for feeding hot water to a manual hot water tap 7 are connected respectively. The water inlet channel 5 is provided with a water flow amount sensor 8 for detecting the amount of water flowing to the heat exchanger 2 and an incoming water temperature thermistor 9 for detecting the incoming water temperature. A warm thermistor 10 is provided.

A fuel supply path 11 for the burner 3 is provided with an electromagnetically operated on-off valve 12 for interrupting the supply of fuel, and an electromagnetically operated gas amount control valve 13 which is capable of changing and controlling the fuel supply amount (burning amount of the burner 3). In the vicinity of the burner 3, an igniter 14 as an ignition means for executing an ignition process for the burner 3 and a frame rod 15 as a flame detection means for detecting whether or not the burner 3 is ignited are provided respectively. Have been.

The remote control operating unit R includes an operation switch 16 for instructing start / stop of the operation of the hot water supply unit K, a temperature setting switch 17 capable of changing and setting a target temperature for tapping, and a display for displaying tapping temperature and target temperature. The system is provided with a unit 18, an operation lamp 19 for displaying an operation state, a combustion lamp 20 for indicating that the burner 3 is in a combustion state, and the like.

The control section H includes a microcomputer, and controls ignition of the burner 3 by ignition control means 100, normal combustion control during hot water supply, and ventilation of the fan 4. The ventilation state determining means 102 for determining the state, the ignition restraining means 103 for restraining the ignition process for the burner 3, the combustion state determining means 104 for determining whether the combustion state of the burner 3 is normal, and the combustion of the burner 3 It is provided with a combustion control restraint means 105 for stopping.

In the ignition mode in which the burner 3 is ignited, the ignition control means 100 controls the amount of drive electric power supplied to the fan 4 so that the fan 4 reaches the target number of revolutions for ignition. The burner 3 is configured to ignite the burner 3 by controlling the amount of gas. More specifically, when the water flow sensor 8 detects a water flow to the heat exchanger 2, the supply of drive power to the fan 4 is started, and the rotation speed detected by the rotation speed sensor 4a becomes the target rotation speed for ignition. In this manner, the feedback control is executed such that the actual rotation speed of the fan 4 is adjusted to the target rotation speed for ignition by adjusting and controlling the supply amount of the driving power of the fan 4. That is, PI control is executed based on the deviation between the detected rotation speed and the target rotation speed for ignition. Further, the intermittent valve 12 is opened and the gas amount adjusting valve 13 is opened and adjusted so as to obtain the ignition gas amount, and the igniter 14 executes the ignition process on the burner 3 and confirms the ignition by the flame rod 15. I do.

In the normal combustion mode after the ignition mode, the normal combustion control means 101 adjusts the combustion amount of the burner 3 so that the hot water temperature reaches the target hot water supply temperature, and adjusts the combustion amount to an appropriate amount for the combustion amount. It is configured to control the rotation speed of the fan 4 so that the rotation speed of the fan 4 becomes the target rotation speed for normal combustion so that the combustion air is passed through. More specifically, when ignition is detected by the frame rod 15, detection information of each of the incoming water temperature thermistor 9, the outgoing water temperature thermistor 10, and the flow rate sensor 8, and the target set by the temperature setting switch 17. Based on the information on the temperature, the amount of combustion of the burner 3 required to bring the hot water supply temperature to the target temperature is calculated.

Then, the gas amount adjusting valve 13 is adjusted and controlled so that the gas amount corresponds to the obtained combustion amount, and the number of revolutions of the fan 4 is set to a proper combustion state with respect to the adjusted gas amount. The amount of drive power supplied to the fan 4 is controlled so as to achieve the target rotation speed. In this way, the gas amount and the ventilation amount are each adjusted and controlled, and hot water at the target temperature is supplied from the hot water tap 7.

In the ignition mode, the ventilation state determination means 102 calculates the integrated value D of the drive power supply amount adjusted from the start of driving the fan 4 to the control of the target number of revolutions for ignition.
s, the ventilation state of the fan 4 is determined based on the integrated value Ds, and the fan 4 is controlled based on the drive power value Dm when the fan 4 is controlled to the target rotation speed for ignition.
It is configured to determine the ventilation state of.

More specifically, after the driving of the fan 4 is started, the driving power supply amount is integrated every set time,
This integration is performed until the rotation speed of the fan 4 reaches the target rotation speed for ignition, and the integrated value D of the drive power supply amount adjusted from the start of driving of the fan 4 to the control of the target rotation speed for ignition.
Find s. If the calculated integrated value Ds is equal to or less than the abnormality determination value D1, it is determined that the ventilation is abnormal, and if the integrated value Ds is equal to or greater than the normal determination value D3, it is determined that the ventilation is normal. The integrated value Ds is equal to the normal judgment value D3.
If it is less than and larger than the abnormality determination value D1, it is determined that the airflow is in the middle state. And, in the ventilation intermediate state,
If the integrated value Ds is equal to or less than the intermediate determination value D2 set between the abnormality determination value D1 and the normal determination value D3, it is determined that the vehicle is in a quasi-abnormal state. It is determined that the state is normal.

Incidentally, the abnormality judgment value D1, the intermediate judgment value D2,
Since the value of the normal determination value D3 varies depending on the type of fuel gas and the pressure loss condition (difference in exhaust cylinder diameter and length) of the supply / exhaust passage for combustion air, the setting can be changed to a different value. .

Thus, based on the integrated value Ds of the driving power supply amount adjusted from the start of driving of the fan 4 to the control of the target number of revolutions for ignition, the ventilation state of the fan 4 is changed to the normal ventilation state. Since the four states of the quasi-normal state, the abnormal ventilation state, and the quasi-abnormal state are determined, the ventilation state of the fan 4 can be accurately determined. In the quasi-abnormal state and when the ignition of the burner 3 is not confirmed, if the drive power value Dm when the fan 4 is controlled to the target rotational speed for ignition is smaller than the set value Dt for abnormality determination, the ventilation state Is determined, the abnormality of the ventilation state can be more reliably determined. The setting value Dt is also configured to be changeable for the same reason as described above.

The ignition restraint means 103, when the ventilation state determination means 102 determines that the ventilation state is abnormal,
The ignition processing for the burner 3 is controlled. More specifically, if it is determined that the ventilation state is abnormal, an error indication of air supply / exhaust obstruction is displayed on the display unit 18, the supply of drive power to the fan 4 is stopped, and the fan 4 is stopped. Close the valve 12 and the gas amount control valve 13,
Subsequent ignition processing of the burner 3 by the igniter 14 is suppressed.

In this way, if it is determined that the ventilation state is abnormal, the ignition process can be stopped, and it is possible to prevent the occurrence of an abnormality such as explosion ignition due to the abnormality of the ventilation state. . Further, as mentioned above,
Since the ventilation state is more reliably determined, it is possible to more reliably prevent the occurrence of an abnormality due to the abnormality of the ventilation state.

After the ignition of the burner 3 is confirmed in the monitoring mode, the combustion state determining means 104 determines whether or not the combustion state of the burner 3 is normal based on the current value of the flame rod 15. It is configured as follows. That is, while the monitoring flag is ON, the current value of the frame rod 15 is monitored until the set time after the ignition of the burner 3 is confirmed by the frame rod 15 has elapsed. If it is less than or equal to a predetermined value, it is determined that the combustion state is abnormal.

When the combustion state is judged to be abnormal by the combustion state judging means 104, the combustion control check means 105 displays an error on the display section 18 and displays the intermittent valve 1.
2 and the gas control valve 13 are closed to stop the combustion of the burner 3. In this way, even when the combustion state of the burner 3 is abnormal, the combustion of the burner 3 can be stopped.
In addition, a stable state can be obtained.

The control operation of the controller H will be described with reference to the flowcharts of FIGS. First, after the operation switch 16 is turned on (step 1), the hot water tap 7 is turned on.
When the water flow (water flow) to the heat exchanger 2 is detected as the detection value of the water flow rate sensor 8 exceeds the set water flow (step 2) as the opening operation is performed, the ignition mode is entered and the fan 4 And the integration of the drive power supply amount of the fan 4 is started (step 3).

Then, based on the rotation speed sensor 4a, feedback control is performed to adjust the driving power supply amount so as to reach the target rotation speed for ignition so that the rotation speed of the fan 4 becomes the target rotation speed. Adjustment control (Step 4,
5). When performing the rotation speed adjustment control, if the target rotation speed for ignition does not reach the target rotation speed for a set time after the start of the supply of the drive power, the supply of the drive power to the fan 4 is stopped. Then, a fan drive error is displayed on the display unit 18 (steps 6 and 7).

When the rotational speed of the fan 4 reaches the target rotational speed for ignition, an integrated value Ds of the drive power supply adjusted from the start of driving of the fan 4 to the control of the target rotational speed for ignition is obtained. If the integrated value Ds is equal to or greater than the normality determination value D3, it is determined that the ventilation is normal. If the integrated value Ds is smaller than the normality determination value D3, the monitoring flag is turned on (steps 5, 8, and 9).
9). If the integrated value Ds is larger than the intermediate determination value D2, it is determined that the vehicle is in the quasi-normal state, and the intermediate determination value Ds is determined.
If it is less than 2, it is determined that the vehicle is in a quasi-abnormal state, and it is determined whether or not the integrated value Ds is less than or equal to an abnormality determination value D1 (steps 10 and 11).

That is, the integrated value Ds is equal to the abnormality determination value D1.
If it is below, it is determined that the ventilation is abnormal, the supply of the driving power to the fan 4 is stopped, and a supply / exhaust blockage error is displayed on the display unit 18 (steps 11 and 12). If the integrated value Ds is larger than the abnormality determination value D1, it is determined that the vehicle is in a quasi-abnormal state. Then, in this quasi-abnormal state, if the drive power value Dm in a state where the target rotational speed for ignition is controlled is smaller than the set value Dt for abnormality determination, it is determined that the ventilation state is abnormal, and The supply of drive power to the fan 4 is stopped, and a supply / exhaust blockage error is displayed on the display unit 18.
(Steps 13 and 12).

When it is not determined that the ventilation state of the fan 4 is abnormal, a pre-purge is performed by the fan 4 in a state of being controlled to the target number of revolutions for ignition, the intermittent valve 12 is opened, and the gas amount adjusting valve 13 is activated. The valve opening is adjusted so that the gas amount becomes equal, and the first ignition process is executed by the igniter 14 (steps 14 and 15). If ignition is not detected by the frame rod 15 and the drive power value Dm at that time is equal to or greater than the set value Dt, the second ignition process is executed in the same manner as the first ignition process (step 1).
6, 17, 19, 15).

If ignition is not detected by the frame rod 15 even after the second ignition process is executed, an error display such as non-ignition is displayed on the display section 18 (steps 15 to 15).
18). Also, in the first ignition processing, when the ignition is not detected by the frame rod 15 and the driving power value Dm at that time is smaller than the set value Dt, the intermittent valve 12 and the gas amount adjusting valve 13 are closed. Thereafter, the fan 4 is also stopped, and a supply / exhaust blockage error is displayed on the display unit 18 (steps 17, 19, 20).

When the ignition is detected by the frame rod 15 and the monitoring flag is turned on, the monitoring mode is entered, and the current value of the frame rod 15 is monitored to determine whether the current value is unstable or not. If the value is equal to or less than the value, it is determined that the combustion state is not normal, the intermittent valve 12 and the gas amount control valve 13 are closed, the fan 4 is also stopped, and an error is displayed on the display unit 18 (step). 16, 21, 2
2, 18).

When the monitoring flag is not turned on or when the combustion state is normal, the normal combustion mode is entered.
Based on the detection information of each of the incoming water temperature thermistor 9, the outgoing water temperature thermistor 10, and the flow rate sensor 8, and the information of the target temperature set by the temperature setting switch 17,
The combustion amount of the burner 3 required to bring the hot water supply temperature to the target temperature is calculated. Then, while adjusting and controlling the gas amount adjusting valve 13 so that the gas amount corresponds to the obtained combustion amount, the target rotation speed for normal combustion at which the number of revolutions of the fan 4 becomes an appropriate combustion state with respect to the adjusted gas amount. The amount of drive power supplied to the fan 4 is adjusted so that the number becomes equal to the number (steps 21 to 23).

The control for adjusting the gas amount and the ventilation amount is performed by closing the hot water tap 7 or by turning the operation switch 16 ON.
This is executed until the FF operation is performed (steps 23 to 2).
5). That is, when the hot water tap 7 is closed or the operation switch 16 is turned off, the intermittent valve 12 and the gas amount adjusting valve 13 are closed to stop the burner 3 from burning, and then the fan 4 is also stopped. (Steps 24-26).

As described above, the abnormality of the ventilation state or the combustion state is reliably determined, and the ignition processing and the combustion of the burner 3 are stopped, so that the burner 3 is not burned in the abnormal state. As a result, the combustion of the burner 3 can be properly performed, and the occurrence of an abnormality due to an abnormality in the ventilation state or the combustion state can be reliably prevented.

[Another Embodiment] (1) In the above embodiment, the fan 4 is controlled based on the integrated value Ds of the driving power supply amount adjusted from the start of driving of the fan 4 to the control of the target rotation speed for ignition. Although the ventilation state is determined to be four states, the state to be determined is not limited to four, and may be five or more or three or less. That is, any device that determines the ventilation state of the fan 4 based on the integrated value Ds may be used. For example, it may be configured to determine two states, a normal ventilation state and a ventilation abnormal state, depending on whether the integrated value Ds is equal to or greater than a determination value for ventilation abnormality determination.

(2) In the above embodiment, the ventilation state is divided into four stages based on the integrated value of the driving power supply amount of the fan 4, and in the quasi-abnormal state, the target rotation speed for ignition of the fan 4 is determined. Although it is configured to determine the ventilation abnormality based on the driving power value Dm at the time of the control, the ventilation state is based on the integrated value of the driving power supply amount of the fan 4, the ventilation normal state, the ventilation intermediate state, It may be configured to divide into three stages of the ventilation abnormal state, and to determine the ventilation abnormality based on the drive power value Dm when controlling to the target rotation speed for ignition of the fan 4 in the intermediate ventilation state. .

(3) In the above embodiment, even if the ignition process for the burner 3 is executed twice and the ignition is not detected,
Although the configuration is such that a misfire error is displayed, the number of times of the ignition processing for the burner 3 is not limited to two, but may be one, or three or more.

(4) In the above embodiment, the monitoring flag is set to O
In the monitoring mode being set to N, the frame rod 15
Is monitored so as to determine the combustion state of the burner 3. However, not only in the monitoring mode, the combustion state may be constantly monitored, and the combustion state of the burner 3 may not be determined. You may comprise.

(5) In the above embodiment, an example is shown in which the combustion control device of the present invention is applied to a hot water supply device. However, the present invention is not limited to the hot water supply device, but may be applied to other combustion devices.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a water heater.

FIG. 2 is a flowchart showing a control operation.

FIG. 3 is a flowchart showing a control operation.

[Explanation of symbols]

 Reference Signs List 3 burner 4 fan 4a rotation speed detection means 14 ignition means 15 flame detection means H control means

Claims (7)

[Claims] 1. A fan for passing combustion air through a burner, a rotation speed detecting means for detecting a rotation speed of the fan,
Control means for adjusting the amount of drive power supplied to the fan to control the number of revolutions of the fan, wherein the control means ignites the burner by feedback control based on information detected by the number of revolutions detection means In the ignition mode, the drive power supply amount is adjusted so that the fan reaches the target rotation speed for ignition, and in the normal combustion mode after the ignition mode, the drive power supply amount is adjusted so as to reach the target rotation speed for normal combustion. A combustion control device configured to control a supply amount, wherein the control means adjusts a drive power in the ignition mode from a start of driving of the fan to a control of a target rotation speed for the ignition in the ignition mode. A combustion control device configured to determine an integrated value of a supply amount and determine a ventilation state of the fan based on the integrated value. 2. The air conditioner according to claim 1, wherein the control means determines a ventilation state of the fan, a ventilation abnormal state in which the integrated value is equal to or less than an abnormality determination value,
A normal ventilation state in which the integrated value is equal to or greater than a normal determination value set as a value greater than the abnormality determination value, and a ventilation intermediate state in which the integrated value is less than the normal determination value and greater than the abnormality determination value. The combustion control device according to claim 1, wherein the combustion control device is configured to make a determination in steps. 3. The control means determines a quasi-abnormal state when the integrated value is equal to or smaller than an intermediate determination value set between the abnormality determination value and the normal determination value in the intermediate ventilation state. The combustion control device according to claim 2, wherein when the integrated value is larger than the intermediate determination value, the combustion control device is configured to determine a quasi-normal state. 4. In the quasi-abnormal state, the control means determines that the drive power is abnormal when the drive power value when the fan is controlled to the target rotational speed for ignition is smaller than a set value for abnormality determination. The combustion control device according to claim 3, wherein the combustion control device is configured as follows. 5. An ignition process for igniting the burner is stopped when the control means detects the ventilation abnormal state and when the control means determines an abnormality based on the drive power value in the quasi-abnormal state, In the normal ventilation state, the quasi-normal state, and the quasi-abnormal state, when it is not determined to be abnormal based on the drive power value, the ignition unit is operated to perform an ignition process of igniting the burner. 5. The combustion control device according to claim 4, wherein: 6. The control means controls the fan to reach an ignition target rotation speed if the flame detection means for detecting the combustion state of the burner does not detect ignition of the burner during execution of the ignition processing. It is configured to determine whether or not the drive power value at the time of control is smaller than the set value for abnormality determination, and if so, determine that there is a ventilation abnormality and stop the ignition process. 6. The combustion control device according to 4 or 5. 7. The burner according to claim 6, wherein the control means is configured to stop the combustion of the burner when the flame detection means that detects the ignition of the burner determines that the combustion state of the burner is not normal. Combustion control device.