During the operation of the fuel gas steam generator, due to improper use by managers, abnormal combustion of the equipment may occasionally occur. What should be done in this case? Nobeth is here to teach you how to deal with it.
Abnormal combustion is manifested in secondary combustion and flue gas explosion at the end of the flue. It mostly occurs in fuel gas steam generators and pulverized coal steam generators. This is because unburned fuel objects are attached to the heating surface and, under certain conditions, can catch fire again. Rear-end combustion often damages the heat exchanger, air preheater, and induced draft fan.
Secondary combustion factors of fuel gas steam generator: Carbon black, pulverized coal, oil and other easily combustible objects can be deposited on the convection heating surface because the fuel atomization is not good, or the pulverized coal has large particle size and is not so easy to burn. Enter the flue; when igniting or stopping the furnace, the furnace temperature is too low, which may lead to insufficient combustion, and a large number of unburned and easily combustible objects are brought into the flue by the flue gas.
The negative pressure in the furnace is too large, and the fuel stays in the furnace body for a short time and enters the tail flue before it has time to burn. The temperature of the tail end flue is too high because after the tail end heating surface is adhered to easily combustible objects, the heat transfer efficiency is low and the flue gas cannot be cooled; the easily combustible objects oxidize and release heat at high temperatures.
When the fuel gas steam generator is under low load, especially when the furnace is shut down, the flue gas flow rate is relatively low, and the heat dissipation conditions are not good. The heat generated by the oxidation of easily combustible objects accumulates, and the temperature continues to rise, causing spontaneous combustion, and the flue various Some doors, holes or windshields are not tight enough, allowing fresh air to leak in to aid combustion.
Manufacturers of fuel and gas steam generators stated that they should try to avoid flame swings from stimulating low-frequency vibrations in the smoke column and must improve the burner structure and combustion conditions. They should first ensure that the ignition front end of the flame is stable and the combustible gas nozzle expands into a hollow cone-shaped air flow. And entrain sufficient high-temperature flue gas to flow back.
Post time: Dec-05-2023
