JP2000146174A - Combustion controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continue combustion while preventing a dangerous combustion like occurrence of a large quantity of CO by outputting a fault detection signal when an oxygen concentration becomes a predetermined value when a maximum supply signal is output, and stopping a combustion equipment when the concentration becomes that corresponding to a CO generating state. SOLUTION: An oxygen sensor 13 is arranged in an exhaust tube 6. The sensor 13 detects an oxygen concentration in an exhaust gas. A control board 14 outputs a control signal to a butterfly valve 9 for fuel and a butterfly valve 11 for air based on the concentration and a set value or the like. The board 14 outputs a maximum supply signal when fully closed valves 9, 11 are detected. When the concentration becomes a forecast concentration corresponding to the state of no optimum combustion state during its continuous operation control, a fault detection signal is output and the forecast is displayed on a display means 18. Further, when the concentration becomes a dangerous concentration corresponding to a CO generating state, an alarm is displayed and a combustion of a combustion equipment is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device for controlling a combustion device for performing combustion using air and fuel, and more particularly to a combustion control device which can be suitably used in an industrial furnace such as a metal melting furnace. The present invention relates to a control device.

[0002]

2. Description of the Related Art FIG. 7 is a configuration diagram showing the configuration of a conventional combustion device and combustion control device disclosed in Japanese Patent Application Laid-Open No. 7-12333. In this figure, 1 is a combustion furnace in which combustion is performed, 2 is a gas pipe for supplying fuel gas to the combustion furnace 1,
4 is a blower for supplying air to the combustion furnace 1, and 29 is a blower 4
A vaporizing cylinder, which is formed integrally with the combustion furnace 1 and mixes air and fuel and burns in the combustion furnace 1, 30 is a heat exchanger, and 6 is an exhaust pipe for discharging exhaust gas from the combustion furnace 1.

An oxygen sensor 13 is provided in the exhaust pipe 6 and detects the oxygen concentration in the exhaust gas. A reference numeral 31 designates the amount of air supplied by the blower 4 and the gas pipe 2 based on the oxygen concentration and the target air-fuel ratio. Is an air-fuel ratio control unit that controls the supplied fuel amount. Further, in the air-fuel ratio control unit 31, 3
Reference numeral 2 denotes a limiter that stops when the rotational speed control amount of the motor of the blower 4 deviates from a predetermined range, and 33 deactivates the combustion when the allowable air-fuel ratio provided for the target air-fuel ratio deviates from the range. It is a limiter to make.

Next, the operation will be described. The air and the fuel gas are mixed in the vaporization cylinder 29 and are burned in the combustion furnace 1. The exhaust gas generated by the combustion is exhausted from the exhaust pipe 6 after using the heat in the heat exchanger 30.
After the combustion is stabilized so as to reach the target air-fuel ratio set based on a certain sequence, a new target air-fuel ratio is set based on, for example, the difference between room temperature and the set temperature, and the new target air-fuel ratio is set. The supply amounts of air and fuel gas are controlled based on the air-fuel ratio and the oxygen concentration in the exhaust gas detected by the oxygen sensor 13.

[0005] During such an operation, if the control amount of the rotation speed of the motor of the blower 4 is out of a predetermined range, the limiter 32 operates to stop the combustion. Similarly, when the current air-fuel ratio is out of the range of the allowable air-fuel ratio provided for the target air-fuel ratio, the limiter 33 operates to stop the combustion.

[0006]

Since the conventional combustion control apparatus is configured as described above, the combustion state determined based on the oxygen concentration in the exhaust gas is determined as an inappropriate combustion state set in advance. If this happens (if the air-fuel ratio is out of the allowable air-fuel ratio range), the combustion will be stopped.

Therefore, in the conventional combustion control apparatus, when the combustion state becomes an improper state set in advance, the combustion is suddenly stopped irrespective of the reason. Although it is possible to prevent dangerous combustion, etc., that occurs in the furnace, in industrial furnaces such as metal melting furnaces, if the combustion is stopped, the molten metal will solidify in the crucible As a result, since the damage is increased before the industrial furnace is operated again, there is a demand to continue the combustion as much as possible, and there has been a problem that such a demand cannot be sufficiently satisfied.

[0008] The inventors of the present invention have conducted intensive studies to solve this problem. As a result, the oxygen concentration corresponding to a state in which CO is generated in the exhaust gas and the oxygen concentration corresponding to a state other than the optimum combustion state are found. The inventors have found that there is a difference that can be detected by an oxygen sensor or the like, and have completed the present invention.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to prevent the dangerous combustion such that a large amount of CO is generated while continuing the combustion as much as possible. An object of the present invention is to obtain a combustion control device that can be suitably used in an industrial furnace such as a furnace.

[0010]

A combustion control device according to the present invention includes a fuel control device for controlling an amount of fuel supplied to the combustion device, an air control device for controlling an amount of air supplied to the combustion device, Oxygen concentration detecting means for detecting the oxygen concentration in the exhaust gas discharged from the combustion device, and controlling the amount of air supplied by the air control means based on the oxygen concentration so as to attain a predetermined air-fuel ratio corresponding to the amount of supplied fuel. Control means for performing
Maximum supply detection means for detecting that the air supply means is in the maximum supply state and outputting a maximum supply signal, and outputting an abnormality detection signal when the oxygen concentration reaches a predetermined value while the maximum supply signal is being output. Abnormality detection means, a prediction means for issuing a prediction based on the abnormality detection signal, and, in a state where the maximum supply signal is output, stop the combustion of the combustion device when the oxygen concentration becomes a concentration corresponding to the CO generation state. And combustion stopping means.

[0011] A combustion control device according to the present invention comprises a fuel control means for controlling the amount of fuel supplied to the combustion device, an air control means for controlling the amount of air supplied to the combustion device, and the air discharged from the combustion device. Oxygen concentration detection means for detecting the oxygen concentration in the exhaust gas, control means for controlling the amount of air supplied by the air control means and the amount of fuel supplied by the fuel control means so as to achieve a predetermined air-fuel ratio based on the oxygen concentration, Maximum supply detection means for detecting that the air control means is in the maximum supply state and outputting a maximum supply signal, and minimum supply detection means for detecting that the fuel control means is in the minimum supply state and outputting a minimum supply signal And an abnormality detecting means for outputting an abnormality detection signal when the oxygen concentration reaches a predetermined value in a state where the maximum supply signal and / or the minimum supply signal are output; And the forecast means that emits a forecast by Zui,
In a state where the maximum supply signal and / or the minimum supply signal are output, a combustion stopping means for stopping the combustion of the combustion device when the oxygen concentration becomes a concentration corresponding to the CO generation state.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a configuration of a combustion device and a combustion control device according to Embodiment 1 of the present invention.
In the figure, 1 is a combustion furnace (combustion device) in which combustion is performed,
2 is a gas pipe for supplying fuel gas to the combustion furnace 1, 3 is an air pipe for supplying air to the combustion furnace 1, 4 is a blower for sending air to the air pipe 3, and 5 is air preheated by the heat of the combustion furnace 1. A burner that mixes fuel gas and air later and burns in the combustion furnace 1 is an exhaust pipe that discharges exhaust gas from the combustion furnace 1. The combustion method of preheating the air to perform combustion is called a regenerative burner system and has high energy efficiency.

In the gas pipe 2, 7 is a safety shut-off valve, 8
Is a cock provided between the safety shut-off valve 7 and the burner 5; 9 is a fuel butterfly valve with an actuator provided between the cock 8 and the safety shut-off valve 7 (fuel control means, minimum supply detection Means 10 is a fuel flow sensor provided between the safety shut-off valve 7 and the fuel butterfly valve 9.

In the air pipe 3, reference numeral 11 denotes an air butterfly valve with an actuator (air control means, maximum supply detection means) provided between the blower 4 and the burner 5.
Reference numeral 2 denotes an air flow sensor provided between the blower 4 and the air butterfly valve 11.

An oxygen sensor (oxygen concentration detecting means) 13 is provided in the exhaust pipe 6 for detecting the oxygen concentration in the exhaust gas. A fuel butterfly valve 9 is provided based on the oxygen concentration and the set value. And a control panel that outputs a control signal to the butterfly valve 11 for air. In the control panel 14, reference numeral 15 denotes a controller provided on the control panel 14, 1
6 is a sensor controller for correcting and setting the detection characteristics of the oxygen sensor 13 and the like. 17 is a burner controller for outputting a control signal to the fuel butterfly valve 9 and the air butterfly valve 11 based on the oxygen concentration and the set value. Control means, combustion stopping means, abnormality detecting means) and display means (forecasting means) 18 for displaying information on the combustion operation state by the burner controller 17.

FIG. 2 is a sectional view showing the structure of the butterfly valves 9 and 11 with the actuator according to the first embodiment of the present invention. FIG. 3 is a perspective view showing a structure of a limit mechanism of an actuator section of butterfly valves 9 and 11 with an actuator according to Embodiment 1 of the present invention.

In these figures, reference numeral 19 denotes each of the pipes 2 and 3
And a valve shaft 21 having a butterfly valve 20 is rotatably provided. Reference numeral 22 denotes an actuator. Reference numeral 23 denotes an actuator shaft which is connected to the valve shaft 21 by a joint 24 and is rotated by a motor and a train wheel 25. Reference numeral 23a denotes an actuator shaft head. Reference numeral 26 denotes a cam for outputting a minimum supply signal or a maximum supply signal by operating the microswitch 27 in the maximum supply state or the minimum supply state of the butterfly valve 20, for example.
It is fixed to the actuator shaft head 23a so as to be freely positioned by an adjusting screw 26b inserted into the adjusting hole 26a. Here, since the position of the cam 26 fixed by the adjusting screw 26b is the maximum supply signal generation position, the maximum supply signal generation position does not necessarily have to match the maximum opening of the valve itself. For example, it is possible to set so that the maximum supply signal is generated at a position where the opening degree of the valve itself is 90%. It goes without saying that the same applies to the minimum supply signal generation position. The cam 26 can be formed by, for example, sheet metal bending. Reference numeral 27a denotes a lever for turning on / off the microswitch 27, and reference numeral 27b denotes a roller rotatably supported by the lever 27a and in contact with the cam 26. These actuator shaft 23, cam 2
6. The microswitch 27 and the like are provided in the case 28. Each of the butterfly valves 9 and 11 outputs a maximum supply signal when it detects a fully open state, and outputs a minimum supply signal when it detects a fully closed state. In the first embodiment, the limit state of the fully open / fully closed state is detected based on the limit switch structure. The closed limit state may be detected.

Next, the operation will be described. FIG. 4 is a flowchart showing a control operation of the burner controller 17 according to the first embodiment of the present invention. In the first embodiment, when the oxygen concentration in the exhaust gas is 3% to 5%, the optimum combustion range is achieved, and the oxygen concentration in the exhaust gas is 2% based on the operating characteristics of the regenerative burner system. % Or less (hazardous concentration), CO starts to be generated.
While controlling the supply air amount so as to be 3% to 5% in the target fuel amount), when the oxygen concentration becomes between 2% to 3% (forecast concentration), a forecast display is performed, and the oxygen is further displayed. When the concentration becomes 2% or less, the control operation is performed so as to stop the combustion urgently.

In the figure, ST1 is a fuel amount judging step for judging whether or not the current supplied fuel amount is the target fuel amount, and ST2 is a fuel butterfly when the current supplied fuel amount is the target fuel amount. ST3 is a fuel valve stop processing step for stopping the valve 9, ST3 is a fuel difference determination step for determining whether the current supply fuel amount is smaller than the target fuel amount, and ST4 is a fuel difference stop step for determining whether the current supply fuel amount is the target fuel amount. A fuel valve opening control step of opening the fuel butterfly valve 9 by a predetermined amount when the fuel supply amount is smaller than the amount, and closing the fuel butterfly valve 9 by a predetermined amount when the current supplied fuel amount is larger than the target fuel amount. This is a fuel valve closing control step. By repeating this control, the fuel butterfly valve 9 is set to a predetermined fuel supply amount, which is the target fuel amount.

ST6 is an optimum combustion determination step for determining whether or not the detected value of the oxygen concentration in the exhaust gas is within the optimum combustion range of 3% to 5%. ST7 is the optimum combustion range in which the current combustion is performed. This is an air valve stop step for stopping the air butterfly valve 11 in some cases.

ST8 is a dangerous concentration determination step for determining whether the oxygen concentration is lower than 2%. ST9 is an air valve fully open for determining whether the maximum supply signal is output from the air butterfly valve 11. It is a decision step, ST
Reference numeral 10 denotes an alarm lockout step for performing a control operation so as to cause an emergency stop of combustion when the maximum supply signal is output from the butterfly valve 11 for air and outputting an emergency stop alarm on the display means 18 when the maximum supply signal is output from the butterfly valve 11 for air. Yes,
ST11 is a dangerous concentration, but the butterfly valve for air 11
This is an air valve opening control step of opening the air butterfly valve 11 by a predetermined amount when the maximum supply signal is not output from.

ST12 is a predicted concentration determination step for determining whether the oxygen concentration is 2% or more and less than 3%,
ST13 is an air valve fully open determination step for determining whether or not the maximum supply signal is output from the air butterfly valve 11, and ST14 is the predicted concentration and the maximum supply signal is output from the air butterfly valve 11. This is a forecast processing step of outputting an abnormality detection signal in the case and displaying a forecast indicating that the oxygen concentration cannot be controlled on the display means 18, and when the maximum supply signal is not output from the butterfly valve 11 for air although it is the forecast concentration. It proceeds to the air valve opening control step of ST11.

ST15 is a step of judging whether the minimum supply signal is output from the air butterfly valve 11 or not. ST16 is a step of judging from the air butterfly valve 11 even if the oxygen concentration is 5% or more. This is a control abnormality processing step of determining that the control system is abnormal when the minimum supply signal is output, and displaying the abnormality on the display means 18.
17 is an air valve closing control step for closing the air butterfly valve 11 by a predetermined amount when the oxygen concentration is 5% or more.

Therefore, in the first embodiment, by repeating this control, the supply air amount is controlled so as to be in the optimum combustion range while giving priority to the control of the supply fuel amount, and the final control is performed. In this case, the fuel butterfly valve 9 is set to a predetermined supplied fuel amount which is a target fuel amount, and the combustion operation can be continuously performed at the predetermined supplied fuel amount.

During the continuous operation control, when the oxygen concentration becomes a predicted concentration corresponding to a state that is not the optimum combustion state, an abnormality detection signal is output to display the forecast on the display means 18, and the oxygen concentration is further reduced. When the dangerous concentration corresponding to the CO generation state is reached, an alarm is displayed and the combustion of the combustion device can be stopped.

As described above, according to the first embodiment, the actuator that detects that the air butterfly valve 11 has the maximum opening and outputs the maximum supply signal and the maximum supply signal are output. In the state, the oxygen concentration is C
When the concentration corresponding to the O generation state is reached, the combustion of the combustion device is stopped. When the maximum supply signal is output, and when the oxygen concentration becomes a concentration corresponding to a state other than the optimal combustion state, an abnormality detection signal is output. Since the burner controller 17 for outputting the output and the display means 18 for performing a forecast display based on the abnormality detection signal are provided, it is possible to prevent dangerous combustion such as generating a large amount of CO, and furthermore, to prevent such a risk. It is possible to notify in advance that the danger exists during the combustion operation before the state is reached. As a result, the driver of the combustion device can recognize that there is a possibility of reaching a dangerous state based on the notification, and, for example, set a target fuel amount or the like so as to continue combustion as much as possible according to the situation. There is an effect that the combustion can be adjusted by changing it.

In the first embodiment, an example has been described in which an abnormality detection signal is directly input from the burner controller 17 to the display means 18.
And the display means 18 may be arranged apart from each other, and communication between them may be performed by a communication means or the like to display a forecast display or an alarm display at a remote place.

In the first embodiment, a butterfly valve is used to adjust the amount of supplied air. However, any valve capable of adjusting the amount of air may be used. May be used.

Further, in the first embodiment, it is determined whether or not the oxygen concentration is 2% or more and less than 3% (by judging that the optimum combustion state (3% or more) is not satisfied). Although the detection signal is output, the range of the oxygen concentration that generates the abnormality detection signal is not limited to this.
As long as the value is at least larger than the oxygen concentration (here, 2%) used for the determination of combustion stoppage (failure determination), the effect of the forecast can be obtained as in the first embodiment.

Embodiment 2 FIG. 5 and 6 are flowcharts showing the control operation of the burner controller 17 according to Embodiment 2 of the present invention. In the figure, ST18
Is a fuel amount determination step for determining whether or not the current supply fuel amount is the target fuel amount. ST19 is an air valve fully open determination for determining whether or not the maximum supply signal is output from the air butterfly valve 11. ST20 is a forecast concentration determination step for determining whether or not the detected value of the oxygen concentration in the exhaust gas is 2% or more and less than 3%.
Reference numeral 21 denotes a fuel valve fully closed determining step for determining whether or not the minimum supply signal is output from the fuel butterfly valve 9. ST22 is a predicted concentration and the air butterfly valve 1
This is a prediction processing step of outputting an abnormality detection signal when the maximum supply signal is output from 1 and the minimum supply signal from the fuel butterfly valve 9 and displaying a display indicating that the oxygen concentration cannot be controlled on the display means 18. This is a fuel valve closing control step of closing the fuel butterfly valve 9 by a predetermined amount in order to maintain the air-fuel ratio. In ST24, the target supply fuel amount is maintained since the fuel butterfly valve 9 is closed in order to maintain the air-fuel ratio. This is a fuel amount abnormality prediction processing step of displaying on the display means 18 that the fuel cell cannot be performed.

ST25 is a dangerous concentration determination step for determining whether or not the oxygen concentration is lower than 2%. ST26 is a step for determining whether or not the minimum supply signal is being output from the fuel butterfly valve 9. It is a closing judgment step, and S
T27 is a dangerous concentration, and when the maximum supply signal is output from the air butterfly valve 11 and the minimum supply signal is output from the fuel butterfly valve 9, a control operation is performed so as to stop combustion immediately, and an emergency stop warning is displayed. Means 18
Is an alarm lockout step to be displayed in ST2
Reference numeral 8 denotes a fuel valve closing control step for closing the fuel butterfly valve 9 by a predetermined amount in order to maintain the air-fuel ratio.
Is a fuel amount abnormality prediction processing step for displaying on the display means 18 that the target supply fuel amount cannot be maintained because the fuel butterfly valve 9 is closed to maintain the air-fuel ratio.

ST30 is an optimum combustion judging step for judging whether or not the oxygen concentration is in the optimum combustion range of 3% to 5%. ST31 is a step for judging whether the present combustion is in the optimum combustion range. And fuel butterfly valve 9
ST32 is a valve stop step for stopping the fuel butterfly valve 9 and closing the air butterfly valve 11 by a predetermined amount in the air-rich state in which the oxygen concentration of the exhaust gas is higher than 5%. This is a rich suppression processing step.

ST33 is a non-optimal combustion determination step for determining whether or not the oxygen concentration is in a non-optimal combustion range of 3% or less. ST34 stops the fuel butterfly valve 9 when oxygen is insufficient. And an air-poor suppression processing step of opening the air butterfly valve 11 by a predetermined amount.
ST35 is an optimal combustion determination step for determining whether or not the oxygen concentration is within the optimal combustion range of 3% to 5%.
Reference numeral 6 denotes a valve stop step for stopping the air butterfly valve 11 and the fuel butterfly valve 9 when the current combustion is within the optimum combustion range. ST37 determines whether or not the minimum supply signal is output from the air butterfly valve 11. In step ST38, when the minimum supply signal is output from the air butterfly valve 11 even though the oxygen concentration is 5% or more, it is determined that the control system is abnormal and displayed. ST39 is an air valve closing control step for stopping the fuel butterfly valve 9 and closing the air butterfly valve 11 by a predetermined amount when the oxygen concentration is 5% or more.

Step ST40 is an excess fuel amount determining step for determining whether or not the current supplied fuel amount is larger than the target fuel amount. ST41 is for determining whether or not a minimum supply signal is being output from the fuel butterfly valve 9. ST42 is an alarm processing step for displaying an alarm due to an abnormality in the fuel supply system on the display means 18 when excessive fuel is supplied although the fuel should have been closed. Is a fuel valve closing control step of stopping the air butterfly valve 11 and closing the fuel butterfly valve 9 by a predetermined amount.

Step ST44 is a fuel valve fully open determination step for determining whether or not the maximum supply signal is output from the fuel butterfly valve 9. ST45 is a state where the fuel is excessively supplied and the fuel valve is fully opened. In this case, an alarm processing step for displaying an alarm indicating that fuel control is impossible on the display means 18, and ST46 is a fuel valve opening control step for opening both the air butterfly valve 11 and the fuel butterfly valve 9 by a predetermined amount. Other configurations and operations are described in the first embodiment.
The description is omitted.

Therefore, in the second embodiment, by repeating this control, control is performed so that the supplied fuel amount becomes the target value while giving priority to the control of the air-fuel ratio so as to obtain the optimum combustion range. Finally, the fuel butterfly valve 9 is set so as to supply a predetermined supplied fuel amount which is a target fuel amount, and the combustion operation can be continuously performed at the predetermined supplied fuel amount.

During the continuous operation control, when the oxygen concentration is no longer in the optimum combustion state, an abnormality detection signal is output to display a forecast on the display means 18, and further, the oxygen concentration is changed to the dangerous concentration corresponding to the CO generation state. Then, an alarm is displayed and the combustion of the combustion device can be stopped.

As described above, according to the second embodiment, the actuator for detecting that the air butterfly valve 11 has the maximum opening and outputting the maximum supply signal, and the fuel butterfly valve 9 having the minimum opening And the actuator that detects the temperature and outputs the minimum supply signal, and in a state where the maximum supply signal and the minimum supply signal are output, when the oxygen concentration becomes a concentration corresponding to the CO generation state, the combustion device is activated. A burner controller 17 for stopping combustion and outputting an abnormality detection signal when the oxygen concentration becomes a concentration corresponding to a state that is not the optimal combustion state in a state where the maximum supply signal and the minimum supply signal are output, Since the display means 18 for displaying a forecast based on the abnormality detection signal is provided, dangerous combustion such as generation of a large amount of CO can be prevented. Sealed while, moreover, can be pre-informed that that there risk during combustion operation before reaching such a risk. Therefore, the driver of this combustion device can recognize that there is a possibility of reaching a dangerous state based on this notification, and for example, changes the target fuel amount and the like so as to continue combustion as much as possible according to the situation. This has the effect of adjusting the combustion.
In the above-described embodiment, an example in which the combustion control device according to the present invention is applied to a metal melting furnace has been described. However, the application of the combustion control device according to the present invention is not limited to this, and a steam boiler or hot water The present invention can be applied to a wide range such as a boiler device such as a boiler or an industrial furnace for heat treatment.

[0039]

As described above, according to the present invention, the maximum supply detecting means for detecting that the air control means is in the maximum supply state and outputting the maximum supply signal, and the maximum supply signal are output. In the state, when the oxygen concentration reaches a predetermined value in the state where the maximum supply signal is output, together with the combustion stopping means for stopping the combustion of the combustion device when the oxygen concentration reaches the concentration corresponding to the CO generation state, the abnormality detection signal Is provided, and a forecasting means for issuing a forecast based on the malfunction detection signal is provided, so that dangerous combustion such as generating a large amount of CO is prevented by the combustion stopping means, and During the combustion operation before reaching such a dangerous state, the abnormality detection means and the prediction means can notify in advance of the danger. Therefore, the driver of this combustion device can recognize that there is a possibility of reaching a dangerous state based on this notification, and can adjust the combustion so as to continue the combustion as much as possible according to the situation. There is.

According to the present invention, the maximum supply detecting means for detecting that the air control means is in the maximum supply state and outputting the maximum supply signal, and the minimum supply means for detecting that the fuel control means is in the minimum supply state. Minimum supply detection means for outputting a supply signal, and combustion stop for stopping combustion of the combustion device when the oxygen concentration reaches a concentration corresponding to the CO generation state in a state where the maximum supply signal and / or the minimum supply signal is output. Means for outputting an abnormality detection signal when the oxygen concentration reaches a predetermined value in a state where the maximum supply signal and / or the minimum supply signal are output,
Prediction means for issuing a forecast based on the abnormality detection signal is provided, so that dangerous combustion such as generating a large amount of CO is prevented by the combustion stop means, and before such dangerous state is reached. During the combustion operation, the abnormality detection means and the prediction means can notify in advance that the danger exists. Therefore, the driver of this combustion device can recognize that there is a possibility of reaching a dangerous state based on this notification, and can adjust the combustion so as to continue the combustion as much as possible according to the situation. There is.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a combustion device and a combustion control device according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view showing a structure of a butterfly valve with an actuator according to Embodiment 1 of the present invention.

FIG. 3 is a perspective view showing a structure of a limit mechanism of an actuator section of the butterfly valve with the actuator according to the first embodiment of the present invention;

FIG. 4 is a flowchart showing a control operation of the burner controller according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing a control operation of a burner controller according to Embodiment 2 of the present invention (part 1).

FIG. 6 is a flowchart showing a control operation of a burner controller according to Embodiment 2 of the present invention (part 2).

FIG. 7 is a configuration diagram showing a configuration of a conventional combustion device and a combustion control device.

[Description of Signs] 1 Combustion furnace (combustion device) 9 Butterfly valve for fuel (fuel control means, minimum supply detection means) 11 Butterfly valve for air (air control means, maximum supply detection means) 13 Oxygen sensor (oxygen concentration detection means) 17) Burner controller (control means, combustion stop means,
Abnormality detection means) 18 Display means (Prediction means)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobumasa Iwabuchi 2-12-19 Shibuya, Shibuya-ku, Tokyo F-term 3K003 TC07

Claims (2)

[Claims] A fuel control unit for controlling an amount of fuel supplied to the combustion device; an air control unit for controlling an amount of air supplied to the combustion device; and oxygen in exhaust gas discharged from the combustion device. Oxygen concentration detecting means for detecting a concentration, control means for controlling the supply air amount by the air control means so as to have a predetermined air-fuel ratio corresponding to the supply fuel amount based on the oxygen concentration, and the air control means A maximum supply detecting means for detecting that the maximum supply state is present and outputting a maximum supply signal; and outputting an abnormality detection signal when the oxygen concentration reaches a predetermined value in a state where the maximum supply signal is output. Abnormality detection means; a prediction means for issuing a prediction based on the abnormality detection signal; and a state in which the oxygen concentration corresponds to a CO generation state in a state where the maximum supply signal is output. Combustion control device including a combustion stopping means for stopping the combustion in the combustion device If a. 2. A fuel control device for controlling an amount of fuel supplied to the combustion device; an air control device for controlling an amount of air supplied to the combustion device; and oxygen in exhaust gas discharged from the combustion device. Oxygen concentration detecting means for detecting the concentration; control means for controlling the amount of air supplied by the air control means and the amount of fuel supplied by the fuel control means so as to attain a predetermined air-fuel ratio based on the oxygen concentration; Maximum supply detecting means for detecting that the control means is in the maximum supply state and outputting a maximum supply signal, and minimum supply detecting means for detecting that the fuel control means is in the minimum supply state and outputting the minimum supply signal In the state where the maximum supply signal and / or the minimum supply signal are output, if the oxygen concentration becomes a concentration corresponding to a state other than the optimal combustion state, an abnormal detection is performed. Abnormality detection means for outputting an outgoing signal; forecasting means for issuing a forecast based on the abnormality detection signal; and a state in which the oxygen concentration is a CO generation state in a state where the maximum supply signal and / or the minimum supply signal are being output. And a combustion stopping means for stopping the combustion of the combustion device when the concentration of the fuel becomes a concentration corresponding to the above.