Ignition method for circulating fluidized bed boiler

Abstract

The invention provides an ignition method for a circulating fluidized bed boiler. In the ignition start, the thickness of a bed material is 60-80 cm, a primary air volume is adjusted to 24-260,000 Nm3 / h to ensure uniform fluidization of the bed material, after the fluidization of the bed material is uniform, the primary air volume is gradually reduced to 18,200,000 Nm3 / h, so that the bed materialis in the bubbling bed state, an ignition oil pressure is adjusted to 1.2-1.4MPa, and an ignition oil gun with a flow rate of 1200kg / h is used for igniting; during the ignition heating process, more than 90% of primary air is heated by the ignition oil gun to reduce cold air entering a furnace to not cool the bed material; when the bed temperature rises to 420-440 DEG C, pulse coal injecting is conducted; when the bed temperature rises to 620-650 DEG C, the oil gun is gradually withdrawn, and after the combustion is stabilized, the primary air volume is adjusted to be no less than 240,000 Nm3 / h to ensure normal fluidization of the bed material; when the bed temperature reaches 680-700 DEG C, coals are continuously injected, and normal combustion is entered. The ignition method can reduce the amount of fuels required for ignition.

Description

technical field [0001] The invention relates to the technical field of circulating fluidized bed boilers, in particular to an ignition method for circulating fluidized bed boilers. Background technique [0002] Supercritical circulating fluidized bed unit boiler has many advantages such as high efficiency, energy saving and low pollution, wide fuel adaptability, high combustion efficiency, high-efficiency desulfurization, low NOX emission, simple structure and convenient operation. The coal types in Baise Youjiang District generally have low calorific value and other characteristics, making the 2×350MW supercritical circulating fluidized bed unit the first unit in Guangxi Zhuang Autonomous Region. The ignition and start-up of circulating fluidized bed boiler system in the prior art mainly adopts diesel ignition. figure 1 As shown, it usually leads the oil pipe for fuel oil to the ignition oil gun located in the boiler air duct, the fuel oil system 20 and the compressed air ...

AI Technical Summary

Problems solved by technology

During the start-up and operation of circulating fluidized bed boilers, there are common problems such as difficult ignition, easy overheating, easy coking, and large amount of fuel consumption for ignition.

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