Fluidized bed semi-coke heat carrier system and method for preventing boiler from being contaminated

Abstract

The invention relates to a fluidized bed semi-coke heat carrier system and method for preventing a boiler from being contaminated. The system can perform semi-coke heat carrier raw coal pyrolysis by adopting a heating lifting tube, a heat semi-coke tank and a pyrolysis reactor. According to the system combined with a fluidized bed, raw coal is firstly mixed with high temperature semi-coke in the pyrolysis reactor so as to be subjected to high temperature pyrolysis, and volatilizable alkali chloride is volatilized into pyrolysis gas, so that the content of alkali metal in firing coal of the fluidized bed is reduced, the alkali metal inside combustion flue gas is further reduced, and the situation that convection heating surfaces are contaminated is fundamentally solved or greatly alleviated; meanwhile, a sodium resource can be collected when the pyrolysis gas passes through a purification device, and the purified pyrolysis gas and tar are fed into the fluidized bed to be combusted, so that combustible components in coal are effectively utilized, and the combustion efficiency of the boiler is ensured.

Description

technical field [0001] The invention relates to the field of fluidized bed technology, in particular to a fluidized bed semi-coke heat carrier system and method for preventing boiler contamination. Background technique [0002] my country's power generation industry is dominated by thermal power generation, with thermal power installed capacity exceeding 70%. Circulating fluidized bed combustion technology has the advantages of low pollution control cost, wide fuel applicability, and large load adjustment range. When burning high-alkaline coal, the alkaline compounds present in the coal will be volatilized during the combustion process. , easy to condense on the heating surface of the boiler to form sintered or bonded ash deposits, causing corrosion, slagging and contamination of equipment on the heating surface of the boiler. Slagging and contamination will reduce the heat transfer efficiency of the boiler, affect the output of the boiler, and seriously reduce the oper...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a fluidized bed semi-coke heat carrier system and method for preventing boiler contamination, which can effectively solve the contamination problem of the convective heating surface of the existing power plant boiler, reduce the difficulty of boiler heating surface layout, and ensure that the boiler heating surface Sufficient heat exchange and stable boiler output; avoid overheating of the convective heating surface caused by contamination, greatly reducing the occurrence of tube explosion accidents; realize large-scale pure combustion utilization of high-alkaline coal without affecting the combustion efficiency of the boiler

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