JP2002257338A - Combustion controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion controller in which the frequency of short error occurring through adhesion/deposition of impurities or soot to/on a frame rod is decreased and abnormal combustion including misfiring can be detected surely. SOLUTION: The combustion controller comprises a control means 19 for shutting down a burner by detecting abnormal combustion thereof based on a signal from the frame rod 16 and stopping the driving of a fuel supply means 9 and a combustion fan 18. Since the control means 19 is provided with a flame detection control means 27 for interrupting power supply to the frame rod 16 when the burner reaches a predetermined combustion state and sustaining interruption of power supply to the frame rod 16 or resuming power supply thereto depending on the temperature detected by a temperature sensor 17, adhesion of impurities or soot can be reduced, short error can be prevented as much as possible and combustion can be interrupted surely at the time of abnormality.

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 provided with a flame rod for detecting abnormal combustion by utilizing ionic current of a flame.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Utility Model Application Laid-Open No. 61-89649, a voltage is applied to a frame rod inserted in a combustion flame and the flame is applied through the combustion flame. Abnormal combustion including misfire is detected by all flame voltages to stop the combustion.

[0003]

By the way, in this conventional apparatus, impurities and soot floating in the flame are constantly charged by the applied voltage during combustion, so that the soot adheres to the surface of the flame rod, and gradually. There is a problem that the frequency of short-circuit error detection increases due to accumulation on the burner and contact with the burner.

[0004]

In order to solve the above-mentioned problems, the present invention focuses on this point and, in particular, comprises a burner for burning fuel, a fuel supply means for supplying fuel to the burner 1, A combustion fan that supplies air, a frame rod that is inserted into the combustion flame of the burner and detects a flame voltage by applying a voltage through energization, a temperature sensor that detects the temperature of the burner, and abnormal combustion of the burner by a signal from the flame rod In the one provided with control means for stopping the driving of the fuel supply means and the combustion fan to extinguish the burner, when the combustion of the burner reaches a predetermined combustion state, The power supply to the frame rod is stopped, and the continuation of the power supply to the frame rod and the resumption of the power supply are controlled in accordance with the temperature detected by the temperature sensor. Those having a detection controller.

[0005] As a result, the flame rod is not always energized, so that the adhesion of impurities and soot is reduced, and in the event of an abnormality, the energization of the frame rod is resumed. Is confirmed, control of continuation or stop of combustion is performed, and reliable safety control is performed.

Further, the temperature sensor detects the temperature of the burner at predetermined intervals, compares this detected temperature with the previous detected temperature, and restarts energization to the frame rod when the difference is out of a predetermined temperature range. By doing so, there is no fear of overlooking abnormal combustion of the burner, and confirmation by the frame rod can be performed immediately.

Further, the temperature sensor detects the temperature of the burner at predetermined intervals, and if the detected temperature exceeds predetermined upper and lower limits, energization to the frame rod is resumed, thereby causing abnormal combustion. In the easy state, the combustion detection is always performed by the flame rod, and the flame rod can be used with ease.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A combustion control device according to the present invention will be described below with reference to an embodiment shown in the drawings. Reference numeral 1 denotes a bottomed cylindrical pot burner constituting a burner, which has a primary air hole 2 and a secondary air hole 3 at a lower portion of a peripheral wall, and an outer periphery of which is covered by an outer cylinder 5 via an air chamber 4.

Reference numeral 6 denotes a flame regulating cylinder placed at the center of the pot burner 1, which promotes mixing of the vaporized gas and the combustion air. 7
Is an ignition heater which also serves as a preheating heater provided at the bottom of the pot burner 1 and is constituted by a rod-shaped ceramic heater;
A vaporizer for vaporization 8 is placed on the lower part.

Reference numeral 9 denotes an oil leveler for storing fuel oil on a constant oil level. The oil leveler 9 pumps fuel oil by an electromagnetic pump 11 constituting fuel supply means provided on the upper lid 10 and supplies the fuel oil to the pot burner 1 via a supply pipe 12.

Further, the tip of the supply pipe 12 has a small-diameter injection pipe 13 which is inclined downward into the pot burner 1.
And is provided in a protection cylinder 14 fixed to the outer cylinder 5 and penetrating the side wall of the pot burner 1, and a tip portion of the protection cylinder 14 is provided.
And injects the supplied fuel oil to one end of the vaporizing layer 8.

Numeral 15 denotes an upper cover 10 which is provided in parallel with the electromagnetic pump 11.
Is connected to the supply pipe 12 on the downstream side of the electromagnetic pump 11 and is connected to the supply pipe 1 when the fire is extinguished.
The fuel oil in 2 is returned to the oil leveler 9.

Reference numeral 16 denotes a flame rod which is suspended in the pot burner 1. The flame rod is inserted into the combustion flame, and is applied with a voltage by energization. The flame voltage is detected between the flame and the pot burner 1 to cause ignition, misfire and abnormal combustion. Etc. are detected.

Reference numeral 17 denotes a temperature sensor comprising a thermistor mounted on the back side of the bottom of the pot burner 1. The temperature sensor 17 detects the temperature of the bottom of the pot burner 1 and instructs an ignition operation. It controls the power distribution and prevents abnormal heating.

Numeral 18 denotes a combustion fan for supplying combustion air from the primary and secondary air holes 2 and 3 into the pot burner 1 through the air chamber 4, and is continuously driven to extinguish the pot burner 1 when the fire is extinguished. is there.

Referring now to the electric circuit diagram of this embodiment shown in FIG. 2, reference numeral 19 denotes control means comprising a microcomputer having various functions such as comparison, calculation, memory, and count. The first relay 23 connected to the output side receives an operation instruction from the base board 21, each instruction signal from the temperature sensor 17, and a flame detection circuit 22 for comparing a frame voltage detected by the frame rod 16 with a reference voltage.
Via the first relay switch 23a via the ignition heater 7 and via the second relay 24 the second relay switch 24a
The drive of the combustion fan 18 and the alarm buzzer 26 are controlled via the electromagnetic pump 11, the suction pump 15, and the control element 25.

Numeral 27 is a flame detection control means provided in the control means 19. The combustion of the pot burner 1 is performed in a predetermined combustion state, that is, for 2 minutes 30 seconds in a forced medium heat state,
The third relay switch 28a is opened via the third relay 28 to stop the energization of the frame rod 16, and the temperature detected by the temperature sensor 17 is read at intervals of 20 seconds, and the difference from the previous temperature is ± 5 ° C. or more. When it is determined that there is, or when the detected temperature is 350 ° C. or more of the upper limit, or when the detected temperature is 200 ° C. or less of the lower limit, the energization of the frame rod 16 is restarted via the third relay 28, respectively. A flame detection operation for confirmation by the flame detection circuit 22 is performed, and when the voltage is higher than the reference voltage, it is determined that there is no abnormality, and the energization of the frame rod 16 is stopped again. is there.

Reference numeral 29 denotes a display board for displaying various operations and settings, and displays an error "E1" when the flame detection is abnormal.

Reference numeral 30 denotes the electromagnetic pump 11 and the suction pump 15
, 31 is a power supply circuit, 32 is a transformer, and 33 is an AC power supply.

Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG. Combustion is started in the pot burner 1, and at this time, the flame rod 16 is energized and the ignition is confirmed by flame detection to perform combustion control.

When the combustion becomes stable, step 34 is reached.
Then, the control means 19 causes the combustion to be forced-combustion combustion, and if this combustion has elapsed for 2 minutes and 30 seconds, the process proceeds to step 35 and the flame detection control means 27 stops the energization of the flame rod 16.

Further, in step 36, the thermal power control is performed, and the flame detection control means 27 reads the temperature detected by the temperature sensor 17 at the pot burner 1 at intervals of 20 seconds.
In step 7, the detected temperature is compared with the previous detected temperature (the first detected temperature is the last detected temperature in the previous combustion), and it is determined whether or not the temperature difference is ± 5 ° C. or more.

In this step 37, the temperature difference is ± 5.
If NO within ° C, the process proceeds to step 38 where the temperature sensor 17
Detected the upper limit temperature of 350 ° C, or the lower limit temperature of 2
It is determined whether 00 ° C. has been detected. If both are NO, the process proceeds to step 39, where it is determined whether the operation switch 20 is OFF. If YES, the combustion is stopped in step 40, and NO
If there is, the process returns to step 37 to repeat this operation.

In steps 37 and 38, YE
S, that is, when the temperature detected by the temperature sensor 17 of the pot burner 1 suddenly rises or falls by ± 5 ° C. or more from 20 seconds ago, when the temperature exceeds the upper limit temperature of 350 ° C. or more, or 200 When the temperature exceeds the lower limit temperature of not more than ° C., the flow proceeds to step 41 to restart the energization of the frame rod 16 and to detect the final abnormal combustion by the frame rod 16.

In step 42, the flame detection circuit 22
Compares the frame voltage detected by the frame rod 16 with the reference voltage. If the voltage is not equal to or higher than the reference voltage, it is determined to be abnormal, and if NO, the process proceeds to step 43, where "E1" is displayed on the display board 29, and abnormal combustion The state is notified to the user to call attention, and the process proceeds to step 40 to stop the combustion.
In the case of ES, the process proceeds to step 44, in which the energization of the frame rod 16 is stopped again, and the process returns to step 37.

Therefore, after the stable combustion after the ignition, the energization of the flame rod 16 is minimized, so that the amount of impurities floating in the flame and soot that is charged and deposited on the flame rod 16 is minimized. It is possible to reduce the frequency of short errors and to use it for a long period of time without worry.

Further, abnormal combustion is detected by the temperature detected by the pot burner 1 by the temperature sensor 17, and the final abnormality detection is performed by the frame rod 16, so that the abnormality can be reliably detected, and there is no fear of malfunctioning. Is a good one.

Further, the temperature sensor 17 detects the temperature of the pot burner 1 at predetermined intervals, compares this detected temperature with the previous detected temperature, and when the difference is out of a predetermined temperature range, the temperature sensor 17 applies a signal to the frame rod 16. Since the energization was restarted,
There is no fear of overlooking the abnormal combustion of the pot burner 1, the confirmation can be immediately performed by the frame rod 16, and the delicate abnormal combustion can be accurately detected in a short time.

The temperature sensor 17 detects the temperature of the pot burner 1 at predetermined intervals, and when the detected temperature exceeds a predetermined upper limit temperature and lower limit temperature, the power supply to the frame rod 16 is restarted. In a state where combustion is likely to occur, flame detection is always performed by the frame rod 16,
Abnormal combustion can be detected instantaneously and used with peace of mind.

[0030]

As described above, according to the present invention, energization of the frame rod is minimized, so that impurities and soot floating in the flame are charged and deposited on the frame rod as in the prior art. To minimize the amount of
The frequency of short-circuit errors can be reduced to ensure safe use over a long period of time.Furthermore, abnormal combustion is detected by the temperature of the burner detected by the temperature sensor, and final abnormality detection is performed with the frame rod as before, so it is reliable. It is possible to detect abnormalities and to use without any fear of malfunction.

The temperature sensor detects the temperature of the burner at predetermined intervals, compares the detected temperature with the previous detected temperature, and restarts the energization to the frame rod if the difference falls outside a predetermined temperature range. By doing so, there is no fear of overlooking the abnormal combustion of the burner, the confirmation with the flame rod can be performed immediately, and the subtle abnormal combustion can be accurately detected in a short time.

Further, the temperature sensor detects the temperature of the burner at predetermined intervals, and when the detected temperature exceeds the predetermined upper limit temperature and lower limit temperature, if the energization to the frame rod is restarted, abnormal combustion occurs. In an easy state, flame detection is always performed by the flame rod, abnormal combustion can be detected instantaneously, and it can be used with confidence.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a combustion unit to which an embodiment of the present invention is applied.

FIG. 2 is an electric circuit diagram of the main part.

FIG. 3 is a flowchart of the main part.

[Explanation of symbols]

 Reference Signs List 1 pot burner (burner) 11 electromagnetic pump (fuel supply means) 16 flame rod 17 temperature sensor 18 combustion fan 19 control means 22 flame detection circuit 27 flame detection control means

Continued on the front page F term (reference) 3K003 SA01 SB07 SC02 SC04 SC09 3K005 WA01 WB04 WB10 WC01 WC02 YA13 YA25

Claims (3)

[The claims] 1. A burner for burning fuel, a fuel supply means for supplying fuel to the burner, a combustion fan for supplying combustion air, and a flame voltage which is inserted into a combustion flame of the burner and detects a flame voltage by applying a voltage by energization. A flame rod, a temperature sensor for detecting the temperature of the burner, and a control means for detecting abnormal combustion of the burner based on a signal from the flame rod, stopping driving of the fuel supply means and the combustion fan to extinguish the burner. In this case, when the combustion of the burner reaches a predetermined combustion state, the control means stops the energization of the frame rod, and continues to stop the energization of the frame rod and restart the energization. And a flame detection control means for controlling according to the temperature detected by the temperature sensor. 2. The temperature sensor detects the temperature of the burner at predetermined intervals, compares the detected temperature with the previous detected temperature, and energizes the frame rod when the difference is out of a predetermined temperature range. The combustion control device according to claim 1, wherein the control is restarted. 3. The system according to claim 1, wherein the temperature sensor detects the temperature of the burner at a predetermined cycle, and when the detected temperature exceeds a predetermined upper limit temperature and a lower limit temperature, the energization to the frame rod is restarted. 3. The combustion control device according to claim 2.