Basic technical requirements for dual-fuel burner
Basic technical requirements for dual-fuel burner
Dual-fuel burner is a device that enters the furnace in a certain proportion, speed and mixing mode to realize timely ignition, efficient and clean combustion. This equipment is equipped with a fully automatic combustion device with automatic ignition, flame monitoring and automatic adjustment devices. At present, most of the oil and gas burners used in domestic industrial furnaces are fully automatic burners.
Dual-fuel burner is an important equipment of oil and gas industrial furnace. According to the combustion fuel, it can be divided into oil burner and gas burner, and there are also oil and gas dual-purpose burners with the function of burning two fuels (oil and gas or two different gases). The fuel burner mainly includes fuel injector (atomizer), air conditioner, etc. The gas burner mainly consists of gas nozzle or orifice, regulator, etc.
In order to meet the requirements of combustion process in the furnace and ensure the safety, reliability, efficiency, economy and low pollution emission of the equipment, the burner shall have the following main technical performance:
(1) High combustion efficiency.
In order to ensure the combustion efficiency at high speed, the fuel burner is required to have a good atomization effect within a certain working range, that is, after atomization of oil droplets, the size of oil droplets is uniform, the atomization angle is appropriate, the distribution of oil mist flow density along the circumference is consistent with the air distribution, and the mixing effect of oil mist and air is good.
Under the rated gas pressure, the gas burner shall be able to fully burn through the rated gas volume to reach the rated heat load production.
(2) Reasonable air distribution, stable and sufficient fuel combustion.
The root of the atomizing torch should be supplemented with appropriate amount of air in a timely manner to prevent the oil and gas from decomposing into carbon black through high temperature and low oxygen conditions, and form a reflux zone with appropriate size and location at the outlet of the combustion airflow. The fuel and air should be placed in a higher temperature field to ensure rapid and stable ignition. In the middle and later stages of combustion, the air and oil mist should be mixed quickly and evenly to ensure complete combustion, And the harmful substances (CO, NO, etc.) generated in the combustion flue gas shall be reduced as much as possible.
(3) The shape and length of the combustion flame shall be consistent with the furnace, the flame shall have good fullness, and the flame temperature and blackness shall meet the requirements of the furnace. The flame shall not be allowed to wash the convection heating surface of furnace wall, furnace bottom and outlet window.
(4) Good regulation performance. The burner shall be able to meet the requirements of furnace load regulation, that is, between the minimum load and the maximum load of the furnace, the burner can work stably without flashback and de-fire.
(5) The less energy the nozzle consumes in the atomization process, the better.
(6) The wind resistance of the air conditioning device is small, and the operation noise is small.
(7) The ignition, speed regulation and other operations are convenient, safe and reliable.
(8) The structure is simple, compact, reliable, highly automated and easy to maintain.
The combustion status of oil and gas boilers and furnaces mainly depends on the working performance of burners. Poor atomization quality of oil burner or unreasonable air flow distribution will lead to the following adverse consequences:
(1) Incomplete combustion will pollute the heating surface at the rear of the boiler, and the flue gas temperature will rise and even cause secondary combustion.
(2) The heat loss of incomplete combustion combustible gas increases.
(3) The heat loss of flammable solid combustion increases.
(4) Burner outlet or furnace coking.
(5) Accidents such as flameout, shooting and even furnace explosion occur.