A circular circulating fluidized bed boiler with a built-in tail flue and its driving power generation system

Abstract

The invention discloses a tail flue built-in loop-shaped circulating fluidized bed boiler and a driving power generation system thereof. The boiler comprises a loop-shaped hearth, a tail flue arrangedin a boiler loop-shaped inner cavity and separators symmetrically arranged with respect to the center of the hearth, wherein cold walls are uniformly distributed on an inner ring and an outer ring ofthe loop-shaped hearth, and are divided into a first region cold wall and a second region cold wall according to functional characteristics, and a flue gas mixing chamber, a low-temperature reheater,a primary air preheater, a flue gas cooler and a secondary air preheater are sequentially arranged in the tail flue in the flue gas flow direction. The boiler has the beneficial effects that the structure of the existing boiler is compact and integrated, the boiler island occupied space is reduced about one third, meanwhile, the separators which are symmetrically arranged in the center and the flue gas mixing chamber enable flue gas to be symmetrically collected, so that the uniformity of the load of the separators are effectively increased, according to the gas-solid flow state and the heatdistribution in the hearth, the side wall area and the four-corner area in the hearth the width and the deep direction are divided into heating areas with different functions, energy loss is reduced,and flexible adjustment is realized.

Description

technical field [0001] The invention relates to a circulating fluidized bed boiler and its drive power generation system, in particular to a circular circulating fluidized bed boiler with a built-in tail flue and its drive power generation system. Background technique [0002] During the enlargement process of the circulating fluidized bed coal-fired boiler, the proportion of the heating surface in the high temperature area increases due to the increase rate of the heating area of ​​the boiler furnace is lower than the increase rate of the heat release capacity of the furnace, and the arrangement of the heating surface is difficult. Universal challenge. Simply increasing the heating surface in the furnace may make the heating screens in the furnace too densely arranged, resulting in serious uneven combustion dynamic field and heat transfer in the furnace, which will bring about boiler efficiency and safety problems; while simply increasing the furnace volume capacity will T...

AI Technical Summary

Problems solved by technology

Although a variety of flue expansion designs are adopted, this sequentially converging upper flue structure fundamentally leads to the dynamic state at the outlet of each cyclone separator (especially the cyclone separator located on the same side of the furnace body) Different, which will cause uneven loading of the cyclone separator

Especially in the case of variable operating conditions, this unevenness will be more serious; (2) The increased heating surface will lead to the inhomogeneous distribution of the heat load in the coal-fired boiler along the width and depth of the furnace.

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