CFB radiation mixed boiler capable of reducing contamination of high-alkalinity coal

Abstract

The invention discloses a CFB radiation mixed boiler capable of reducing contamination of high-alkalinity coal. The boiler comprises a fluidized bed hearth, a cyclone separator, a horizontal flue, a radiant boiler body and a convection flue, wherein the fluidized bed hearth is connected with the cyclone separator, the cyclone separator is connected with the radiant boiler body through the horizontal flue, and the bottom of the radiant boiler body is connected with the horizontal convection flue; a radiation water wall and a radiation heat exchange screen are arranged in the radiant boiler body, the radiation water wall is in the structure of a rectangle with a cavity, and the radiation heat exchange screen is located in the cavity. The radiation heat exchange screen comprises a plurality of vertical planar radiation sub-screens, wherein each radiation sub-screen is composed of a plurality of vertical stand tubes in a splicing mode, and the radiation sub-screens are arranged in a divergent mode with the central axis of the water wall as the center of circle. According to the CFB radiation mixed boiler capable of reducing contamination of high-alkalinity coal, the CFB boiler hearth and the radiant boiler body are used in cooperation so that a convection heat exchange surface can be prevented from existing in the interval from 700 DEG C to 1100 DEG C, and contamination caused by combustion of coal with the high content of alkali metal is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of anti-pollution of high-alkaline coal, in particular to a CFB radiation hybrid boiler for reducing pollution of high-alkaline coal. Background technique [0002] my country's power generation industry is dominated by thermal power generation, with thermal power installed capacity exceeding 70%. Thermal power coal mostly uses low-quality and low-grade coal. Slagging of boiler furnace water wall and contamination of convective heating surface are one of the important problems that affect the normal operation of power plant boilers for a long time. Slagging and contamination will reduce the heat transfer efficiency of the boiler, affect the output of the boiler, and seriously reduce the operating safety of the equipment. Severe slagging and contamination may lead to major accidents such as boiler flameout, tube burst, and unplanned shutdown. [0003] In order to prevent various problems caused by slaggin...

AI Technical Summary

Problems solved by technology

The proportion of high-alkaline coal fired in the boiler should not exceed 30%. When the proportion of mixed fired coal increases, the convective heating surface will be seriously contaminated and ash will form a flue gas corridor, and the flue gas will cause leakage of the high-temperature reheater and high-temperature superheater.

Since high-alkaline coal is mostly used in pithead power stations in Xinjiang, the demand for coal blended with foreign coal is large. This method is often limited by transportation conditions, which greatly increases operating costs.

[0007] For traditional power plant boilers, when burning high-alkaline coal, the alkali metal elements rich in coal are easy to deposit on the convective heating surface, so serious contamination occurs on the convective heating surface, resulting in boiler output Insufficient, pipe wall temperature is too high to cause pipe burst and other phenomena

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