Influence of Inclined Secondary Air on Gas-Solid Flows in a W-Shaped Flame Boiler
|School||Harbin Institute of Technology|
|Course||Thermal Power Engineering|
|Keywords||W-shaped Flame Boiler gas-particle two phase flows PDA modeled study injection angle of secondary air|
Reverses of anthracite is abundant in our country. It occupies 16.2% of the whole coal reverse. However, with its low volatile matter, it has difficulty in ignition, stable combustion and burnout. W-shaped flame boiler, which adopts so many technical means as long-flame, classification delivering wind and high concentration factor of pulverized coal, is the preferred style for anthracite and lean coal combustion because of its superiority on adaptability of coal rank, stable ignition and combustion under part load operation and burn-out of fly ash.The modeled study of the characteristics of gas-particle two phase flows has been made with PDA in the 1025 T/H W-shaped flame boiler, which is designed and produced by DongFang Boiler Works according to the technique introduced from F&W Co. Ltd of USA, and studies of regularity on influence of injection angle of secondary air on gas-solid two phase flows in the boiler is made in this paper,It is manifested that when the injection angle of the secondary air is bigger, the gas-solid flows downward route in the chamber of furnace can be increased, this is beneficial to complete combustion of pulverized coal injected into chamber of furnace, but the action of primary air and secondary air washing out rear walls of the furnace can be increased evidently.When the injection angle of secondary air is 25°, increasing the E-secondary air velocity can shorter the length of the pulverized coal goes, meantime, primary air and secondary air washing out rear walls of the furnace shall be increased, E-secondary air velocity being half of F-secondary air velocity is good, it enforces the mixing intensity between the primary and the second air, which may promote the combustion of the pulverized coal.In order to promote the combustion of the pulverized coal, the conclusion is that E-secondary air velocity being half of F-secondary air velocity is good. So some theoretical foundations for the boiler’s operation in practice and configuration optimization are presented.