JPH08145345A - Combustion control device - Google Patents

Abstract

PURPOSE: To achieve the diagnosis by discriminating the abnormality of a spark rod from the abnormality of an ignition transformer based on the value of the primary current of the ignition transformer through the actual measurement and the flame current. CONSTITUTION: An ignition transformer 31 to supply the ignition current to a spark rod 30 facing a pilot burner 29 of a burning equipment and a flame detector 32 to detect the flame signal of the pilot burner 29 are provided, and the abnormality of the spark rod 30 or the ignition transformer 31 is detected by a micro-processor based on the primary current to be supplied to the ignition transformer 31 at the spark check timing before the combustion starts and the flame current based on the detected output of the flame detector 32 at the spark check timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition transformer for supplying spark ignition current and a combustion control device for diagnosing an abnormality of a spark rod in a sequence in which a spark is blown from a spark rod to ignite a pilot burner. .

[0002]

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

[0003]

Since the conventional combustion apparatus is constructed as described above, the individual main burners and pilot burners have structural and performance variations. There is a problem that it is difficult to accurately diagnose the state of the spark rod or the spark even if only the change of the secondary current is detected.

Further, the diagnosis of the primary current cannot be performed when the spark is flying in the same state in a place other than the place where the spark originally flies, and the abnormality of the spark is detected only by the diagnosis of the primary current. There is a problem that it is not possible to determine whether it is due to an abnormality in the rod or due to an abnormality in the ignition transformer.

The present invention has been made in order to solve the above-mentioned conventional problems. Based on the magnitudes of the primary current and the flame current of the ignition transformer, the abnormality of the spark rod and the abnormality of the ignition transformer are measured. An object of the present invention is to obtain a combustion control device capable of distinguishing and diagnosing.

[0006]

A combustion control device according to the present invention is an ignition transformer for supplying an ignition current to a spark rod facing a pilot burner of a combustion device, and a flame detector for detecting a flame signal of the pilot burner. Is provided, the microprocessor is provided with the above based on the primary current supplied to the ignition transformer at the spark check timing before the start of combustion and the flame current based on the detection output of the flame detector at the spark check timing. The abnormality of the spark rod or the ignition transformer is diagnosed.

[0007]

In the combustion control device according to the present invention, the ignition current is caused to flow from the ignition transformer to the spark rod before the start of combustion, and the primary current flowing to the primary side of the ignition transformer is set within the ignition waiting timing before the start of combustion. According to the magnitude of each flame current corresponding to the output signal detected by the flame detector, the microprocessor diagnoses whether the spark rod or the ignition transformer of the ignition system is abnormal,
This contributes to easier maintenance and management of the ignition system.

[0008]

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

Further, 3 is a flame current detector for detecting flame current based on the output of a flame detector which will be described later.
Is an analog / digital converter for converting each detection output of the frame current detection unit 3 and the power supply voltage detection unit 1 into a digital signal.
It is a digital conversion unit.

Further, 5 is a combustion control unit, which receives an ignition / extinction signal converted by the flame current detection unit 3,
A control signal for each combustion sequence is output to the relay output unit 6. The relay output unit 6 outputs a relay control signal for turning on / off a combustion control load 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 primary current detection unit for detecting a primary current of an ignition transformer, which will be described later, based on an output from the relay output unit 6. This detection output is also input to the analog / digital conversion unit 4 and converted into a digital signal. To be done. Reference numeral 8 is a signal input unit for inputting the feedback signal from the relay output unit 6 to a microprocessor described later.

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

In particular, according to the present invention, the microprocessor 9 is based on the flame current detected by the flame detector and the primary current of the ignition transformer, which will be described later, within the ignition waiting timing before the start of combustion. Detect an abnormality in the transformer.

Further, the microprocessor 9 has a function of receiving the feedback signal as described above 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 section 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. 2 shows a combustion device for diagnosing the ignition system of the present invention. In FIG. 2, 21 is a fan for blowing air, 22 is a fan for supplying air to the main burner 25 through the air supply passage 21a. It is a damper that adjusts the air volume.

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 gas supplied to the pilot burner 29.

Further, 30 is the above-mentioned spark rod arranged near the pilot burner 29, 31 is the above-mentioned ignition transformer for supplying an ignition current to the spark rod 30, and
Reference numeral 32 denotes the flame detector which is arranged near the main burner 25 and detects a flame.

Next, the operation will be described. The overall control flow of the combustion control device of the present invention is as shown in the control sequence diagram of FIG. 3, 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 the flame current detector 3 detects the flame current based on the detection signal output from the flame detector 32. The analog / digital conversion unit 4 converts the signal into a digital signal, which is input to the microprocessor 9 to perform abnormality diagnosis of the spark rod 30 and the ignition transformer 31.

The flame current detecting section 3 also converts and outputs an ignition / extinguishing signal based on the flame detection signal, and inputs this signal to the fuel control section 5. The fuel control unit 5 controls the fuel sequence, and the control output thereof is input to the relay output unit 6 to turn on / off the load for fuel control by each relay.

The ignition transformer primary current detection unit 7 detects the primary current of the ignition transformer 31 from the output of the relay output unit 6, and the detected output is also the analog / digital conversion unit 4.
It is taken into the microprocessor 9 via the.

On the other hand, the feedback signal from the relay output section 6 is input to the microprocessor 9 through the signal input section 8.

Therefore, the microprocessor 9 receives the power supply voltage, the frame current, and the feedback signal as inputs, executes data processing of burner failure data and burner failure diagnosis, and stores the result in the memory 10. It can be displayed on the display unit 11 or output to the outside through the communication interface unit 12.

Further, in the sequence of flying the spark from the spark rod 30, the microprocessor 9
The signals of the primary current of the ignition transformer 31 and the flame current detected by the flame current detector 3 are taken in through the analog / digital conversion unit 4, and the abnormality of the ignition system is detected according to the levels of the primary current and the flame current. The presence / absence of an abnormality in the spark rod, an abnormality in the ignition transformer 31, and an abnormality in the primary current detection circuit are diagnosed.

That is, according to the present invention, the ignition waiting timing is provided before the ignition trial timing at which the pre-purge is completed and the combustion is started, and the ignition transformer 31 is supplied with the ignition check timing at the spark check timing set within the ignition waiting timing. The microprocessor 9 diagnoses the abnormality of the spark rod 30 or the ignition transformer 31 based on the next current and the flame current based on the detection output of the flame detector at the spark check timing.

In such an abnormality diagnosis, as shown in Tables 1 and 2, depending on whether the flame detector 32 is in a position where the spark on the spark rod 30 is easily visible or hard to see in the burner structure. The diagnostic process will be executed.

[0029]

[Table 1]

[0030]

[Table 2]

Further, in the case of performing the diagnostic processing based on Tables 1 and 2, the above-mentioned primary current and flame current when the ignition system is normal are learned beforehand according to the burner structure and stored in the memory 10. By doing so, the type of the burner structure is automatically switched, and the optimum table 1
Alternatively, the diagnosis process based on Table 2 can be executed by the microprocessor 9.

FIG. 4 is a flowchart showing the procedure of the above abnormality diagnosis. According to this flowchart, first, the frame current at the spark check timing is learned, and the learning value I _fST of this frame current average is determined (step ST1). ).

Then, it is checked whether or not the learned value I _fST is larger than the set value I _o (step ST2). If the learned value I _fST exceeds the set value I _o , the position where the spark is easily visible is found. The above-mentioned abnormality diagnosis is carried out for the burner structure in (1) based on Table 1 (step ST3).

Further, it is judged whether or not the learning value _Ift is less than or equal to the set value I _O and exceeds the set value I ₁ (step ST
4) If so, perform the above-mentioned failure diagnosis on the structure where the spark is difficult to see based on Table 2 (step ST5). If not, use a burner in which no spark is seen, With only the primary current, that is, when the primary current is small, it is determined to be abnormal, and when the primary current is large, it is determined to be normal (step ST6).

By taking the difference between the actually measured primary current and frame current and the previously learned normal primary and frame currents, the microprocessor 9 can perform diagnostic processing based on Table 1 or Table 2. Can be selectively executed.

FIG. 5 is a flowchart showing a procedure for diagnosing an abnormality in the ignition system according to the present invention. First, at the start of diagnosis, gas pre-purge in the vicinity of the spark rod 30 is carried out (step ST11), and then the ignition transformer 31. More ignition current is supplied to the spark rod 30 (step ST12).

Since the spark rod 30 receives the ignition current to generate the spark, the ignition transformer 3 at this time is generated.
Based on the primary current of No. 1 and the flame current detected by the flame detector 32 and obtained from the flame current detection unit 3, the microprocessor 9 performs the diagnostic process as shown in Table 1 or Table 2. Run.

Then, it is judged whether or not the ignition system is normal from the result of the diagnosis processing (step ST13), and if normal, the combustion operation is made executable (step ST1).
4) On the other hand, when the abnormality is not normal (abnormal), it is then determined whether or not the abnormality is the abnormality of the spark rod 30 (step ST15), and the abnormality of the spark rod 30, that is, the spark is different. If it is flying at this location, the processing after the pre-purge in step ST1 is re-executed.

On the other hand, when the spark rod 30 is normal and the ignition transformer 31 and the primary current detection circuit are abnormal, the burner operation is locked out to avoid danger (step ST16). . In this way, by diagnosing the levels of the primary current and flame current of the ignition transformer 31, it is possible to distinguish between the abnormality of the ignition transformer 31 and the abnormality of the spark rod 30.

[0040]

As described above, according to the present invention, the ignition transformer for supplying the ignition current to the spark rod facing the pilot burner of the combustion apparatus and the flame detector for detecting the flame signal of the pilot burner are provided. Based on the primary current supplied to the ignition transformer at the spark check timing before the start of combustion and the flame current based on the detection output of the flame detector at the spark check timing, the microprocessor is provided with the spark rod or Since it is configured to diagnose the abnormality of the ignition transformer, there is an effect that it is possible to make a diagnosis by distinguishing the abnormality of the spark rod and the abnormality of the ignition transformer from the magnitudes of the primary current and flame current of the ignition transformer measured. is there.

[Brief description of drawings]

FIG. 1 is a block diagram showing a combustion control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a combustion device according to the present invention.

FIG. 3 is a control sequence diagram showing a control procedure of the combustion control device of the present invention.

FIG. 4 is a flowchart showing a procedure of abnormality diagnosis according to the present invention.

FIG. 5 is a flowchart showing a procedure of abnormality diagnosis of the ignition system in the present invention.

[Explanation of symbols]

 9 Microprocessor 29 Pilot burner 30 Spark rod 31 Ignition transformer 32 Flame detector

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

Claims (1)

[Claims] 1. An ignition transformer for supplying an ignition current to a spark rod facing a pilot burner of a combustion apparatus,
A flame detector for detecting the flame signal of the pilot burner, a primary current supplied to the ignition transformer at the spark check timing before the start of combustion, and a frame current based on the detection output of the flame detector at the spark check timing. A combustion control device including a microprocessor for diagnosing an abnormality of the spark rod or the ignition transformer based on the above.