The burner flame monitoring system is a core component that ensures a safe and stable combustion process. Failure can lead to burner malfunction or safety hazards, making rapid diagnosis and troubleshooting crucial. Diagnosis requires a systematic troubleshooting process, from power supply to signal, and from external to internal. Combining flame monitoring principles with burner operating characteristics, the fault can be gradually narrowed down.
Power supply failure is a common cause of flame monitoring system failure. First, check whether the monitoring module's supply voltage is stable. If the voltage fluctuates or is absent, investigate whether the power supply circuit is aging, has poor contact, or has a blown fuse. For example, a chemical plant's burner monitoring system frequently reported malfunctions. Inspection revealed that a loose power socket increased contact resistance, causing voltage fluctuations to cause the monitoring module to restart. Furthermore, correct power polarity must be verified to avoid damaging the monitoring module due to reverse power supply.
The detector, the "eyes" of flame monitoring, directly impacts monitoring effectiveness. If the burner is actually on fire but the monitoring system indicates no fire, first check whether the detector is covered in dust or oil, which could obstruct UV or IR signal reception. In this case, clean the detector's quartz lens with a dust-free cloth and a small amount of alcohol to restore its light transmittance. If the probe lens is damaged, it must be replaced immediately. Do not replace it with ordinary glass, as it cannot transmit the specific wavelengths of light generated by the flame. Furthermore, a probe installed at an angle that is off or too far from the flame can also cause signal attenuation. Adjust the probe position according to the burner manual to ensure it is within the effective monitoring range.
Faults in the signal transmission line are often overlooked, but their impact can be significant. If the monitoring system displays a flame status that differs from the actual flame, check the connecting cable between the probe and the monitoring module for looseness, damage, or moisture. For example, a burner monitoring system at a steel plant falsely reported flame extinguishment. Investigation revealed that aging wiring had damaged the insulation, leading to signal interference and malfunction. In this case, the terminal blocks should be re-crimped or the shielded cable should be replaced to enhance interference resistance. For long transmission lines, it is also important to verify the presence of connectors to avoid signal attenuation due to increased contact resistance.
Faults in the monitoring module itself should be verified by replacement. If the power supply, probe, and wiring are all normal but the monitoring system still does not function, swap the module with one from another functioning burner to see if the fault is transferred. If the fault disappears after replacement, the original module is faulty and should be replaced with a similar model. For example, a thermal power plant's burner monitoring module frequently crashed. Inspection revealed that this was due to aging internal capacitors, leading to unstable power supply. Replacing the module restored the system to normal operation. Additionally, incorrect module parameter settings may also cause failures. Parameters such as sensitivity and delay time need to be adjusted based on the burner's fuel type and flame characteristics.
Changes in burner operating conditions can indirectly affect flame monitoring effectiveness. For example, fluctuations in fuel composition can cause variations in flame color and intensity, potentially exceeding the monitoring module's set thresholds and causing false alarms. In this case, historical burner operating data should be analyzed to analyze the patterns of flame characteristic changes and appropriately adjust the monitoring module's sensitivity or switch to a monitoring mode more appropriate for the current operating conditions. Furthermore, sudden changes in burner load may cause the flame to flicker briefly. The monitoring module must have sufficient anti-interference capabilities to avoid misinterpreting flameout due to transient signal fluctuations.
The impact of environmental factors on flame monitoring systems cannot be ignored. Harsh environments such as high temperature, high humidity, and strong electromagnetic fields can accelerate sensor aging, degrade circuit insulation, or damage module electronic components. For example, a ceramics factory's burner monitoring system frequently malfunctioned in the summer. Investigation revealed that high humidity caused moisture in the wiring, leading to short circuits. In this case, it's necessary to improve ventilation between equipment rooms or install protective devices against moisture, dust, and electromagnetic interference on the monitoring system to extend the equipment's service life.
Daily maintenance and preventive repairs are key to reducing flame monitoring system failures. It's recommended to establish a regular inspection schedule to clean probes, check wiring, test module functionality, and record burner operating parameters to establish a fault database. Data analysis can identify potential faults in advance and enable targeted measures. For example, a chemical company, through monthly functional testing of its burner monitoring system, promptly identified and replaced aging probes, avoiding production accidents caused by monitoring failure.
