Low-NOx stable combustion burner for boiler

Abstract

The invention relates to a low-NOx stable combustion burner for a boiler. The low-NOx stable combustion burner comprises a primary air pipe communicating with a hearth and a peripheral air pipe; a gradual shrinkage pipe, a straight pipe and a gradual expansion pipe are arranged on the section, before inserted in the hearth, of the primary air pipe; the maximum section area of the gradual shrinkagepipe is the same with the maximum section area of the gradual expansion pipe; and the peripheral air pipe sleeves the external of an outlet end of the primary air pipe. Compared with the prior art, the burner can lengthen the flame length and reduce the temperature of a central combustion area, so that generation of heat and fuel NOx is reduced, mutual ignition of burners on the same layer is facilitated, the fuel cost caused by ignition is reduced, uniform distribution of the whole hearth temperature is facilitated, and the coking and slagging problems caused by local high temperature are reduced.

Description

technical field [0001] The invention relates to a burner, in particular to a low NOx stable combustion burner used in boilers. Background technique [0002] With the development of China's economy and people's yearning for a better life, the problem of environmental pollution has become more and more prominent and has received more and more attention. As a major industrial polluter - power plants, under the pressure of environmental requirements, are making various technological innovations to reduce pollutant emissions. More than 85% of my country's current power generation is coal-fired power generation. There are a large number of coal-fired power plants. Under the environmental requirements, technical transformation of each plant is in progress. To reduce NOx, we can start from various aspects, such as flue gas For example, SCR (Selective Catalytic Reduction) denitrification method has high efficiency, but it brings many problems, such as high temperature requirements, d...

AI Technical Summary

Problems solved by technology

The method of providing a blunt body, since the blunt body adds a lot of resistance, the rear rectifying plate also increases the complexity of the burner interior

The air staged combustion technology is good in theory, but the internal combustion situation in the furnace is more complicated. Due to the different quality of coal, it is difficult to control the stable combustion during the initial anoxic combustion.

In addition, the interior of the axial flow type is complex and technically difficult, and it is difficult to apply it to actual industrial production

The simple tapering and diverging pipe makes the primary air immediately generate a great disturbance at the furnace entrance. For the four-corner tangential round boiler, it is not conducive to prolonging the flame stroke, which is not conducive to the mutual ignition effect between the burners on the same floor. In addition, the layering effect of shades is not very obvious, and it is not easy to form a relatively orderly velocity field and concentration field

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