Vertical pulverized coal boiler

Abstract

The invention discloses a vertical pulverized coal boiler which comprises a hearth, at least one pulverized coal burner and a secondary air distribution device, wherein the hearth comprises side wallspositioned at the periphery, and a hearth inner cavity; the hearth inner cavity is positioned at the bottom of the hearth below the side walls and is formed by enclosing the side walls and the bottomof the hearth; each pulverized coal burner comprises a main body and a burner outlet pipe extending from the main body; the burner outlet pipe extends into a lower space in the hearth inner cavity and is applied to introducing a mixture of primary air and pulverized coal into the hearth inner cavity; the secondary air distribution device is arranged at the bottom of the hearth so as to occupy thewhole cross sectional area of the bottom of the hearth and is applied to introducing secondary air into the hearth inner cavity. The mixture of the primary air and pulverized coal and the secondary air are mixed in the hearth inner cavity to form an air-pulverized coal mixture in which plug flow wholly flows upwards.

Description

technical field [0001] The invention relates to the field of boilers, in particular to a vertical pulverized coal boiler. Background technique [0002] my country's coal-based energy structure will not change for a long time in the future. China's annual coal consumption reaches 1.5 billion tons, of which 800 million tons of coal are used for coal-fired thermal power generation and 700 million tons of coal are used for coal-fired industries. boiler. With the improvement of air pollutant emission standards for coal-fired boilers, efficient and clean coal combustion technology is an inevitable requirement for future development. [0003] In addition, in the traditional combustion method, there is a large difference between the primary air and secondary air injection speeds in the furnace and the average speed of the furnace section, and there is a large recirculation zone in the furnace, which can entrain high-temperature flue gas and preheat coal powder, but The control of t...

AI Technical Summary

Problems solved by technology

[0005] In addition, in the traditional combustion method, the jet velocity of the primary air and secondary air in the furnace cavity is quite different from the average velocity of the airflow on the cross-section of the furnace, and there is a large recirculation zone in the furnace cavity, which can entrain high-temperature flue gas. Preheating of pulverized coal, but the control of the recirculation zone is more complicated, and the pulverized coal particles are prone to agglomeration in the recirculation zone. If the flow field organization in the furnace is not good, the furnace slagging tends to be large, which affects the safe and stable operation of the boiler

[0006] In addition, in the tangential combustion method or swirling combustion method of pulverized coal, the combustion temperature of pulverized coal exceeds the ash melting point due to the concentrated combustion and release of heat of pulverized coal, and the combustion of pulverized coal is easy to form slagging, and part of the slag sticks to the furnace On the water wall, affect the heat transfer performance of the boiler

During the operation of the boiler, part of the slag needs to be discharged from the bottom of the furnace, thus reducing the efficiency of the boiler

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