Coal ash and ash combined re-circulating system for preventing boiler from being polluted

Abstract

The invention relates to a coal ash and ash combined re-circulating system for preventing a boiler from being polluted. The coal ash and ash combined re-circulating system comprises a coal ash re-circulating system and an ash re-circulating system; the coal ash re-circulating system is used for leading coal ash out from an outlet of a de-duster and conveying to a coal milling machine; the ash re-circulating system is used for collecting ash of a boiler ash basin to a drier, crushing the dried ash, conveying the crushed ash to an ash storage cabin, and then conveying the ash from the ash storage cabin to the coal milling machine; the coal ash, the ash and raw coal powder are mixed and milled to require size in the coal milling machine according to a certain ratio and then sprayed in a hearth to be burnt; and active Na in smoke is gradually converted into insoluble Na salt with the flowing of the smoke. With the adoption of the coal ash and ash combined re-circulating system, the active Na in the smoke can be fixed, so as to generate the insoluble Na without being condensed and attached onto a convection heated surface; the dirt source is cut off; the convection heated surface is protected to safely operate; the operation time of the boiler is increased; and the benefits and power plants can be improved.

Description

technical field [0001] The invention relates to a technology for preventing boiler contamination, in particular to a fly ash and ash slag combined recirculation system 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%. Most of the coal used in thermal power plants is inferior and low-grade coal, so that it will cause problems such as slagging of the water wall of the boiler furnace and contamination of the convective heating surface. These problems are important factors 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 may lead to major accidents such as boiler flameout, tube burst, and unplanned shutdown. [0003] ...

AI Technical Summary

Problems solved by technology

Due to the occurrence of contamination, the heat transfer resistance of the convective heating surface will increase, resulting in insufficient boiler output and even shutdown of the boiler due to tube explosion.

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