Recently, a customer found us Beijing Chuangwei, consulting low nitrogen burner and ordinary burner advantages and disadvantages, in view of this problem, our technical personnel gave the following answers.
1. Because of stretching the combustion zone, the combustion intensity is weakened and the formation of NO_x is inhibited in a certain period of time.
2, low load combustion stable. Because the air volume at the bottom is reduced, the fuel is also very stable when it burns at low concentration. It can even achieve 40% load stable combustion.
3, low load, furnace flame full degree is better. The water wall is uniform in heat absorption.
1. Because of the position of exhaust air, a large number of air supply does not participate in combustion when leaving the furnace, and this part of hot air also absorbs a large amount of heat from the air preheater, so it will cause the phenomenon of low exhaust temperature. Especially at low load.
2. Because of weakening the air inlet of the lower furnace, the supporting capacity of the lower secondary air is weakened, the slag discharge is increased, and the carbon content of the slag is increased, especially at high load.
3. Because of weakening the inlet air of the lower furnace, the rigidity of the air is weakened, the combustion area is enlarged, and the water wall is easy to coke at high load.
4. Because of the anoxic combustion in the lower part of the furnace, a large amount of reducing gas is produced, which makes the ash melting point lower and even causes the phenomenon of coking in the ash hopper.
5. Due to the stretching of the combustion zone, the superheater will overheat and the cooling water will be insufficient during the high load period, and even cause the screen to be over-coked.
6. As a result of the expansion of a large number of reductive gases and combustion area, the coking in the middle and lower parts of the water wall is serious, and the phenomena of fire extinguishing, deflagration and damage to the dregs dredger caused by decoking all occur.
7. Because the coking at high load affects the heat absorption of the water wall and the temperature of the lower part of the furnace rises, and the burnout air can only cool the flue gas at the upper part of the furnace, but has no effect on the temperature of the lower part of the furnace, the production of NO_x in the lower part of the furnace increases with the coking, the longer the duration of the high load is, the effect of reducing NO_x is reduced. The smaller, even beyond the original NOx.
8. The theory of burning volatile matter in the lower part of the furnace and burning coke in the upper part is inconsistent with the theory of "volatile matter precipitation, volatile matter burning, coke burning, ash peeling off from the surface shell, and volatile matter continuously precipitating out with ash peeling off from the surface shell" in pulverized coal combustion. Therefore, at high load, the combustion time of a large number of pulverized coal is lengthened, and the incompletely burned pulverized coal is taken into the flue. The carbon content of fly ash increases.
Low nitrogen burner can obtain the best combustion parameters by adjusting the combustion air and combustion head. We hope to help you.