Fault phenomenon of biogas generator unit: When starting, it is possible to turn the engine, but the generator unit cannot run on fire.
Fault cause:
1. The biogas pipeline is blocked or has accumulated water, resulting in insufficient intake air; A bypass valve was not closed and air was sucked in, resulting in a biogas concentration below 40%.
2. Insufficient starting battery voltage; Below 24V.
3. The mixer is out of order and seriously deviates from the basic reference point.
4. The intake end solenoid valve is not working, blocking the entry of biogas into the generator.
5. The zero pressure valve at the inlet end is adjusted incorrectly.
6. The actuator is not working or the opening of the actuator lever is too low.
7. There is no feedback signal from the speed sensor.
8. The speed control board has no output signal to the actuator.
9. The ignition module is not working. Aging of spark plugs, carbon deposits, and poor contact of ignition high-voltage wires.
Fault handling:
1. Carefully inspect all pipelines from the biogas digester to the gas storage bag, and then to the gas inlet of the generator set. Check if there are any leaks or air intakes caused by pipeline detachment, valve not closed, etc. Ensure that the pipeline is unobstructed, free from blockages, and water accumulation. If conditions permit, it is best to use a methane analyzer to measure the methane concentration of the biogas. The generator set can only be started and operated when the methane concentration is at least 45% or higher.
2. Check if the battery voltage is sufficient. It needs to be maintained above 25.8V.
3. Check the opening point of the mixer. If it deviates from the basic reference point, it should be adjusted to the basic reference point. During the startup process, if there is a situation where the ignition is about to be successful but not started, the opening of the mixer can be appropriately increased to increase the amount of biogas input. Adjustment range: within 3 teeth; Side wheel and side adjustment.
4. Check whether the intake end solenoid valve can open normally after being powered on. Short circuit the wiring of the solenoid valve in the control box (Line 88) to see if biogas can pass through; Check if the solenoid valve is burnt or stuck, and clean or replace it if necessary.
5. With the biogas connected, measure the biogas pressure behind the zero pressure valve using a horizontal pipe. It should be ensured that the liquid level at the biogas end of the horizontal pipe is basically level with the liquid level at the air end (the biogas end can also be slightly lower by 2-3 millimeters).
6. Observe whether the actuator oscillates while turning. If it cannot swing or the lever opening is not enough, please check whether the wiring of the actuator is connected, whether there is rust or stuck inside the actuator, or if the coil is burnt out; Ensure that the opening position of the speed control lever is not less than 2/3 of the effective stroke of the actuator; Replace the actuator with a new one if necessary.
7. Check if the wiring connection from the speed sensor to the speed control board is secure and reliable; Remove the speed sensor and check if the sensing head is damaged; Measure the resistance value of the sensor (should be between 200 Ω -500 Ω); Check if the installation of the speed sensor meets the requirements, ensuring that the distance between the speed sensor and the flywheel teeth is 0.028-0.042 inches (0.71-1.07mm), which means that the sensor will retract 1/2 to 3/4 turns after contact with the flywheel teeth.
8.During the startup process, measure whether the working power supply of the speed control board is normal (usually 24V); Measure whether the feedback signal of the speed sensor is normal (should not be less than 5V AC); Measure the voltage signal output from the speed control board to the actuator (12V controller not less than 6V, 24V controller not less than 12V).
9. Observe the ignition indicator light of the ignition module during the start-up process of the biogas generator set. Under normal circumstances, the ignition indicator light will continuously flash; If it does not flash, please check if there is a malfunction or poor wiring in the ignition module; Remove the spark plug and check if the gap between the spark plugs is too large and if there is carbon buildup on the electrodes; The gap should be adjusted to remove carbon deposits; Check for aging and poor contact of the high-voltage wire.
Post time: Nov-14-2023