Pulverized coal fired boiler wall type oscillating low NOx over-fire air device

Abstract

The invention discloses a pulverized coal fired boiler wall type oscillating low NOx over-fire air device. Four groups of over-fire air devices are respectively arranged at the periphery of the outer wall of square boiler wall, each over-fire air device is composed of two over-fire air components which are different in width and height, and the four groups of over-fire air devices are arranged at the upper part of combustor region. Each over-fire air component comprises an over-fire air tube, an over-fire air door, an over-fire air speed measurement backrest tube, an over-fire air bellow, an oscillating over-fire air nozzle, a nozzle shaft pin, a nozzle shaft cotter pin, an oscillating regulating mechanism, an oscillating driving pin, an oscillating cotter pin, a boiler wall cover plate, a side wall board and a comb-shaped plate. Over-fire air is arranged on the outer wall of the boiler wall, the stroke of the over-fire air to be mixed with high temperature flame in the boiler is shortened, penetrability of the over-fire air is improved, and the over-fire air nozzle swings left and right, so that the process of mixing the over-fire air with high temperature flame in boiler can be optimized; boiler fume temperature deviation can be adjusted, so that the aim of promoting burning out of pulverized coal is achieved, CO content in smoke and carbon content in fly ash are reduced, and the efficiency of boiler under low NOx operation condition is ensured.

Description

technical field [0001] The invention relates to a burn-off air device, in particular to a swing-type low NOx burn-off air device arranged in a pulverized coal boiler wall. Background technique [0002] In the field of low NOx combustion of pulverized coal boilers, fuel and air are supplied in stages to achieve the purpose of reducing NOx emissions. In the scheme of adopting graded air supply for pulverized coal boilers, a part of the air is separated from the secondary air as the overfired air, so that the lack of oxygen in the main burner area suppresses the formation of NOx, and the combustion air is arranged at a certain position above the main burner area. Do all the wind to ensure complete combustion of coal powder. Since the overburning air is still arranged in a tangential circle at four corners, the journey into the high-temperature torch is long, and the penetration ability is insufficient, which cannot meet the requirements of the overburning air, which affects th...

AI Technical Summary

Problems solved by technology

Since the overburning air is still arranged in a tangential circle at four corners, the journey into the high-temperature torch is longer, and the penetration ability is insufficient, which cannot meet the requirements of the overburning air, which affects the boiler efficiency

In order to increase the penetration capacity of the overfired air, there is also a form in which the overfired air is provided by the booster fan alone, but the complexity of the system and the operating cost are greatly increased

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