Dense-phase back-flushing multiple level NOx combustion method

Abstract

A concentrated opposite blowing multiple classification NOx combustion method of the protection environmental technology area. The invention is that along the furnace height direction fall into the main combustion chamber, reducing area and burnout area, in the main area the wind fall into two shades in a level direction by firebox , a strong wind rip into the furnace burning side, after the promotion is reversed to change, and the secondary wind cut into the furnace, joint with light wind and form rotary stability aerodynamic field, so most of the wind pulverized coal is led to the furnace central region, ultimately in the heater form a light wind wrap a strong wind, a second air parcels light wind, and wind wrap powder situation, a second wind and light wind in the near wall region of water wall form oxidizing atmosphere, away from water wall region the pulverized coal burning. The invention achieves ultra-low NOx emission, while the burning area prevents to slag and ensure the high combustion efficiency etc. characteristics.

Description

technical field [0001] The invention relates to a method in the technical field of boilers, in particular to a method for burning dense and reverse-blown multiple staged NOx. Background technique [0002] At present, my country's power energy is mainly coal-fired thermal power generation, and the combustion of coal will produce a large amount of nitrogen oxides, such as NO and N 2 O, these two substances are generally referred to as NOx. NOx damages the environment, causing acid rain and photochemical smog. At present, technologies for controlling NOx emissions are divided into two categories: controlling the generation of NOx during the combustion process in the boiler furnace and flue gas purification technology, although flue gas purification technology can greatly reduce NOx emissions to 200mg / m 3 Below, but there are problems such as expensive equipment and high operating costs. Although the general low-NOx combustion technology has the advantages of simple implement...

AI Technical Summary

Problems solved by technology

However, these technologies all adopt the secondary air deflection combustion method. If the secondary air deflection is not properly set, it cannot effectively solve the oxygen deficiency near the water cooling wall of the main combustion area, and may easily cause: due to the biased secondary air traction, the primary wind shear When the circle is enlarged, the pulverized coal is easier to adhere to the wall; the rotational momentum in the furnace is enhanced, and the flow deviation at the furnace outlet is increased

The low oxygen concentration in the main combustion area of ​​the overall air classification in the furnace also affects the enhanced ignition and combustion of pulverized coal in the early stage, which is unfavorable for NOx control

Although the setting of the NOx reduction zone of the overall air classification in the furnace plays a vital role in the final effect of NOx emission control in the furnace, the reduction zone is relatively separated from the burnout zone, and the later burnout degree of pulverized coal will be affected

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