Multi-directional jet swirl pulverized coal burner

Abstract

The invention discloses a multi-directional jet-type cyclone pulverized coal burner. The multi-directional jet-type cyclone pulverized coal burner is installed in a bellow on the outer side of a coal-fired boiler and connected with an opening in a combustion chamber water wall. The multi-directional jet-type cyclone pulverized coal burner comprises a primary air pulverized coal nozzle installed in a direction perpendicular to the combustion chamber water wall, the periphery of the primary air pulverized coal nozzle and the opening in the combustion chamber water wall form an annular secondary air flow nozzle, a wall-attached air guide cylinder is arranged in the secondary air flow nozzle, the wall-attached air guide cylinder and the opening in the combustion chamber water wall form an annular wall-attached air jet flow nozzle, and the circulation area of the outlet of the wall-attached air jet flow nozzle accounts for 3-18% of the circulation area of the secondary air flow nozzle. According to the multi-directional jet-type cyclone pulverized coal burner, on the premise that the structure of a conventional cyclone pulverized coal burner is not greatly changed, part of separated secondary air is enabled to form a mobile oxidation air film on the surface of the water wall through adding the wall-attached air guide cylinder, the surface of the water wall on the periphery of the burner is ensured to be in an oxidizing atmosphere, and high-temperature corrosion and coking to the combustion chamber water wall nearby the burner are avoided.

Description

technical field [0001] The invention relates to the technical field of a swirl pulverized coal burner, in particular to a multi-directional jet type swirl pulverized coal burner. Background technique [0002] At present, due to the wide application of low-nitrogen combustion technology in large thermal power boilers, the wall surface coking and high-temperature corrosion of the furnace water wall are becoming more and more serious, which has gradually become an important factor that threatens the safe and stable operation of power plant boilers. Changes in coal quality, pipe wall temperature, and flue gas composition changes near the water wall of the furnace are all factors that cause coking and high temperature corrosion on the water wall of the furnace. In order to meet the environmental protection boiler low-nitrogen combustion requirements of power plants, oxygen-deficient and low-nitrogen combustion air distribution is implemented in the boiler pulverized coal combusti...

AI Technical Summary

Problems solved by technology

In order to meet the environmental protection boiler low-nitrogen combustion requirements of power plants, oxygen-deficient and low-nitrogen combustion air distribution is implemented in the boiler pulverized coal combustion, which is more likely to cause the pulverized coal to burn anoxic near the water wall, forming a high-temperature and reducing atmosphere, and bringing water to the water wall. Serious hidden danger of high temperature corrosion

Especially in the operation process of the boiler with the front and rear walls opposed to each other, due to the swirling flow of the external secondary air jet and the negative pressure zone between the burner and the water wall, the surrounding high-temperature hot flue gas is driven back to supplement, resulting in Coal powder is prone to stick to the wall near the water wall of the furnace, and it is more likely to cause severe high-temperature corrosion and coking on the water wall of the furnace under anoxic conditions. The occurrence of such situations will bring great hidden dangers to the safe and stable operation of the boiler. At the same time, a large amount of maintenance costs are generated every year

In particular, Zhundong coal, which contains a large amount of sodium, potassium and alkali metals, has been widely used in recent years, and it is more likely to cause severe high-temperature corrosion and coking of the furnace water wall when the boiler is fired.

Images