JPH08178276A - Combustion controlling method - Google Patents

Abstract

PURPOSE: To rapidly and effectively grasp the cause of misfire in the sequence of a spark check timing and ignition trial and to realize the expedition and easiness of recovery operation. CONSTITUTION: If the output side relay of an ignition transformer 31 and the output side relay of a pilot valve 27 are not operated at the ignition trial timing of a combustion sequence, it is decided to be the internal fault of a combustion controller. When the primary current of the transformer 31 is abnormal if both the relays are not operated after the decision, the trouble of the transformer 31 is decided. Further, if a flame current diagnosing result is not normal, the malfunction of a spark rod 30 is decided, and sequentially if the flame current diagnosing result is not normal, the malfunction of a pilot burner 29 is decided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to burner failure diagnosis,
In particular, it relates to a combustion control method for diagnosing the cause of non-ignition of a burner.

[0002]

2. Description of the Related Art In a conventional combustion device such as a boiler, a spark is generated in a spark rod by an ignition current generated by an ignition transformer, the spark ignites gas in a pilot burner, and this ignition is followed by gas in the main burner. Is igniting.

Further, near the main burner, there is provided a flame detector including an ultraviolet ray detector for detecting the presence or absence of a flame generated by the main burner or the pilot burner.

By the way, in the above sequence in which the spark is blown from the spark rod and the pilot burner is ignited, misfiring may occur due to various causes. When such misfiring occurs, the misfiring may occur. It was not possible to determine whether the cause was an abnormality in the spark rod, a failure in the ignition transformer, an abnormality in the pilot burner, or an internal failure in the combustion control device.

[0005]

However, in such a conventional combustion control method, in pursuit of the cause and restoration work such as a failure, each device or part is inspected and replaced, or a trial run is repeated. However, the work is very troublesome and requires a lot of time and experience, and the combustion device must be stopped during this period.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and does not ignite in the sequence of spark check timing and ignition trial newly provided before combustion, which is not in the conventional sequence. It is an object of the present invention to obtain a combustion control method capable of promptly and accurately grasping the cause by any number of people and thereby realizing quick recovery work.

[0007]

A combustion control method according to the present invention is a combustion control unit when an output side relay of an ignition transformer and an output side relay of a pilot valve are not operating at the ignition trial timing of a combustion sequence. It is determined that the ignition transformer is faulty when the output relays are operating and the primary current of the ignition transformer is not normal at the ignition trial timing. In addition, if the flame current diagnostic result at the spark check timing is not normal, it is determined that the spark rod is abnormal, and if the flame current diagnostic result is not normal at the ignition trial timing, the pilot burner turns off. It is determined to be abnormal.

[0008]

According to the combustion control method of the present invention, the flame current detection value in the flame current detection section, the primary current detection value in the ignition transformer in the ignition transformer primary current detection section, and the relay output under the control of the combustion control section are provided. Based on the detected value of the contact feedback signal of the pilot valve from the engine, the cause of the misfire is the internal failure of the combustion control unit, the failure of the ignition transformer, the abnormality of the spark rod, the abnormality of the pilot burner, etc. Alternatively, the other abnormality is accurately determined.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing a combustion control device for carrying out the combustion control method of the present invention. In the figure, 1 is a power supply voltage detection unit for detecting a power supply voltage for the combustion control device, 2
Is a flame detector drive circuit for driving a flame detector (not shown).

Further, 3 is a frame current detecting section for detecting a frame current based on the output of the flame detector, and 4 is a conversion of each detection output of the frame current detecting section 3 and the power supply voltage detecting section 1 into a digital signal. It is an analog / digital conversion unit that operates.

Further, reference numeral 5 denotes a combustion control section which is a target of diagnosis of the cause of misfire in the present invention, and receives the ignition / extinguishing signal converted by the flame current detection section 3 to receive the relay output section 6
The control signal for each combustion sequence is output to. The relay output section 6 controls on / off of combustion control loads such as a fan blower, an ignition transformer, a pilot valve, a main valve, and a damper motor by each relay.

Reference numeral 7 denotes an ignition transformer which is an object of diagnosis of the cause of misfire in the present invention by the output from the relay output section 6.
In the ignition transformer primary current detection unit that detects the next current, the detection output is also input to the analog / digital conversion unit 4 and digitally converted. Reference numeral 8 is a signal input unit for inputting the feedback signal obtained from the relay output unit 6 to a microprocessor described later.

Further, 9 is a microprocessor, which measures the average value and deviation value of each flame current for each combustion sequence from the flame current detector 3 and the average value of each flame current in the optimum state of the burner. And a learning value which is a deviation value are compared with each other, and a burner failure or burner failure prediction is diagnosed from the deviation value of each of these data.

Particularly in the present invention, the microprocessor 9
Has a function of identifying (determining) an internal failure of the combustion control unit 5, an ignition transformer, a spark rod, which will be described later, and an abnormality of the pilot burner as one of the causes of misfire at the ignition trial timing or the spark check timing.

Further, the microprocessor 9 has a function of receiving the above-mentioned feedback signal from the relay for controlling the combustion sequence and determining the cause of misfire or the cause of combustion failure.

Reference numeral 10 is a memory for storing the data input to the microprocessor 9 and the learning data, 11 is a display unit for displaying the processing result of the data, diagnostic result, etc., and 12 is the processing result of the data and diagnostic result. It is a communication interface unit that outputs to the outside.

FIG. 3 shows a combustion device having the following ignition transformer, spark rod, pilot burner, etc., which is the object of diagnosis of the combustion control method of the present invention. In FIG. 3, 21 is a fan for blowing air and 22 is air supply. It is a damper that adjusts the amount of air supplied to the main burner 25 by the fan 21 through the passage 21a.

Further, 23 is a damper motor for controlling the opening and closing of the damper 22, 24 is two main valves (combustion valves) for adjusting the flow rate of the gas supplied to the main burner 25 through the gas passage 26, and 27 is through the gas passage 28. These are two pilot valves (fuel valves) that adjust the flow rate of the gas supplied to the pilot burner 29 that is the target of diagnosis of the cause of misfire.

Further, 30 is a spark rod arranged in the vicinity of the pilot burner 29, 31 is an ignition transformer for supplying an ignition current to the spark rod 30, which is a diagnostic object for the cause of misfire, and 32 is arranged in the vicinity of the main burner 25. Is a flame detector that detects a flame.

Next, the operation will be described. The entire control flow of the combustion control method of the present invention is as shown in the control sequence diagram of FIG. 4, and the absorption operation, the start signal, the wind pressure switch on the damper side, the input side such as the high limit and the low limit, and the damper operation. , Damper high, damper low, blower motor, ignition transformer, pilot valve, main valve, alarm, alarm standby and main valve standby output side, display operation, pre-purge, ignition wait, ignition trial, pilot only, main trial , Start timing and end timing of main stable, steady combustion, post purge, etc. are given, and in each of these control flows, in the present invention,
The following combustion control is executed.

That is, the power supply voltage detection unit 1 detects the voltage of the power supply, and the detected output is converted into a digital signal by the analog / digital conversion unit 4 and input to the microprocessor 9. The microprocessor 9 corrects the frame current based on this digital signal.

On the other hand, the flame detector 32 is driven by the flame detector drive circuit 2, and when the ignition trial is ignited or the pilot burner or the main burner is ignited, the flame detector 32 outputs a flame signal based on the detection signal. The current detection unit 3 detects the frame current, and the detection output is also converted into a digital signal by the analog / digital conversion unit 4 and input to the microprocessor 9.

The flame current detector 3 also converts and outputs an ignition / extinction signal based on the flame detection signal,
This is input to the combustion control unit 5. This fuel control unit 5
Then, the fuel sequence is controlled, and the control output thereof is input to the relay output section 6, and the relay controls the load for fuel control on and off.

On the other hand, a feedback signal including an operation signal of the output side relay of the ignition transformer 31 and the output side relay of the pilot valve 27 is input from the relay output section 6 to the microprocessor 9 through the signal input section 8.

Therefore, the microprocessor 9 uses the power supply voltage, flame current, primary current of the ignition transformer 31,
Data processing and diagnosis as described below are executed by using the contact feedback signals as inputs, and the results are stored in the memory 10, displayed on the display unit 11, or externally output through the communication interface unit 12. ing.

Further, according to the present invention, the microprocessor 9 executes the diagnosis of the cause of the misfire according to the procedure for diagnosing the cause of the misfire shown in FIG.

That is, first, it is determined whether or not the output side relay of the ignition transformer 31 and the output side relay of the pilot valve 27 are activated at the ignition trial timing (referred to as IGT in the figure) of the combustion sequence as shown in FIG. , Based on the feedback signal (step ST1, step ST2).

As a result, when it is not operating, it is determined that the internal failure of the combustion control unit 5 (step ST3, combustion control unit failure determination step), while all the output side relays are operating. In step ST4, it is checked whether the primary current of the ignition transformer 31 is normal at the ignition trial timing.

As a result, if the primary current is not normal, it is determined that the ignition transformer 31 has failed (step ST5, ignition transformer failure determination step), while the primary current of the ignition transformer is normal. In this case, the actual measurement data of the average value and the deviation value of the frame at the spark check timing (referred to as SCT in FIG. 1) and the burner normal state (the normal spark rod state) were operated several times to collect the average value and the deviation value. By comparison with the actual measurement data,
It is checked whether or not the frame current diagnosis result is normal (step ST6).

If the flame current diagnostic result is not normal, it is determined that the spark rod 30 is abnormal (step ST7, spark rod abnormal step). On the other hand, if the flame current diagnostic result is normal, the ignition trial is performed. At the timing, it is checked whether or not the frame current diagnosis result is normal (step ST8).

If the result of this determination is that the frame current diagnostic result is not normal, it is determined that the pilot burner 29 is abnormal (step ST9, pilot burner abnormality determination step), and on the other hand, the frame current is detected at the ignition trial timing. If the diagnosis of No. is normal, it is determined as misfire due to other abnormalities (step S
T10).

In determining the state of the primary current of the ignition transformer in step ST3, the value in the normal state of the primary current is stored in addition to the diagnosis based on the level of the primary current. An initial value) may be compared with the value to determine whether the primary current is normal or abnormal.

FIG. 5 shows another embodiment of the present invention. In step ST26, it is judged whether or not the flame current diagnosis result is normal. If NO, it is judged in step ST27 that the pilot burner 29 or the spark rod 30 is abnormal. To do. In addition, other steps ST21 to ST25, ST28
Are the same as steps ST1 to ST5 and ST10 in FIG.

As described above, according to the present invention, the cause of misfire can be accurately investigated in accordance with the above-mentioned diagnostic procedure, so that the recovery work at the time of occurrence of misfire can be quickly performed within a short time of the spark check timing or the ignition trial timing. it can.

[0035]

As described above, according to the present invention, any person can quickly and accurately grasp the cause of misfire by the sequence of spark check timing and ignition trial newly provided before combustion, which is not in the conventional sequence. As a result, restoration work can be speeded up and facilitated, and the downtime of the entire combustion device can be minimized, which contributes to the prevention of the spread of damage due to the shortened downtime of the production equipment. In addition, since it is possible to diagnose in order from the fundamental failure point of the combustion device, there is an effect that the abnormality caused by the root cause can be removed and the failure point can be accurately determined.

[Brief description of drawings]

FIG. 1 is a flowchart showing a combustion control method according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a combustion control device for carrying out the combustion control method of the present invention.

FIG. 3 is a conceptual diagram showing a combustion device which is a target of a cause of misfire according to the present invention.

FIG. 4 is a control sequence diagram showing a control procedure of the combustion control device in FIG.

FIG. 5 is a flowchart showing a combustion manufacturing method according to another embodiment of the present invention.

[Explanation of symbols]

 5 Combustion control unit 27 Pilot valve 29 Pilot burner 30 Spark rod 31 Ignition transformer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hakuichi Kubota 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Toshiya Arai 1-12 Kawana, Fujisawa, Kanagawa Prefecture No. 2 Yamatake Honeywell Co., Ltd. Fujisawa Factory

Claims (2)

[Claims] 1. When the ignition trial timing of the combustion sequence, the output side relay of the ignition transformer and the output side relay of the pilot valve are checked to see if they have operated, respectively, and if they have not operated, it is determined that an internal failure of the combustion control unit has occurred. In the combustion control unit failure determination step and when the output side relays are all operating, it is checked whether the primary current of the ignition transformer is normal at the ignition trial timing. In the ignition transformer failure determination step for determining that there is a failure, and when the primary current of the ignition transformer is normal, it is checked whether or not the flame current diagnostic result at the spark check timing is normal, and if not, the spark rod. And the spark rod abnormality determination step for determining that If the frame current diagnostic result is normal, check whether the frame current diagnostic result is normal at the ignition trial timing, and if not, execute the pilot burner abnormality determination step to determine that the pilot burner is abnormal. Combustion control method. 2. At the ignition trial timing of the combustion sequence, it is checked whether or not the output relay of the ignition transformer and the output relay of the pilot valve have actuated, and if they have not actuated, it is determined to be an internal failure of the combustion control unit. In the combustion control unit failure determination step and when the output side relays are all operating, it is checked whether the primary current of the ignition transformer is normal at the ignition trial timing. In the ignition transformer failure determination step for determining that there is a failure, and when the primary current of the ignition transformer is normal, it is checked whether the flame current diagnosis result is normal at the ignition trial timing. Pie that burner or spark rod determines to be abnormal A combustion control method for performing a lot burner or spark rod abnormality determination step.