A double low type boiler burning high alkali metal coal

Abstract

A double-low type boiler burning high base metal coal comprises a combustion chamber. The combustion chamber is divided into a small-size combustion chamber dense-phase zone and a large-size combustion chamber lean-phase zone. The small-size combustion chamber dense-phase zone is connected with a coal supply system. The large-size combustion chamber lean-phase zone is connected with an inlet flue of a separator. The volume of the large-size combustion chamber lean-phase zone is 5 times larger than that of the small-size combustion chamber dense-phase zone. According to the double-low type boiler burning the high base metal coal, the operation temperature of the combustion chamber and the temperature of an outlet of the separator are reduced through the method that the flow speed of a combustion chamber hollow tower is reduced, the effective height of the combustion chamber is increased, and a base metal enrichment ash discharging system is additionally arranged, so that the temperature of a burning zone is controlled between 650 DEG C and 850 DEG C, the precipitation mode of base metal and compounds of the base metal is changed, the precipitation amount of the base metal and compounds of the base metal is reduced, most gas base metal and compounds of the gas base metal which are generated in the burning process are solidified in flying ash, bottom slag and bed materials, serious ash accumulation and slag accumulation are avoided, and the continuous operation period is prolonged. The double-low type boiler burning the high base metal coal further has the advantages of being low in pollutant emission, free of limitation of the unit volume, wide in coal type adaptation range, low in non-oiling stable burning load, high in burning efficiency, small in bottom slag emission amount and the like.

Description

technical field [0001] The invention belongs to the technical field of clean coal combustion and utilization, in particular to a double-low boiler for burning high-alkali metal coal. Background technique [0002] my country is a country rich in coal resources. The total coal resources are predicted to exceed 5 trillion tons, ranking third in the world. However, most of my country's coal resources are located in Xinjiang and other western regions. In the process of burning coal in Xinjiang and other places, it was found that a considerable number of boiler furnaces, superheaters and reheater areas would form large areas of highly cohesive ash in a short period of time, accompanied by severe high-temperature corrosion, and eventually This caused a large area of ​​the boiler to explode, which directly affected the reliability, safety and economy of the boiler operation. Research has found that the main cause of the above problems is the high content of alkali metals such as so...

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Problems solved by technology

During the process of co-firing, pulverized coal boilers are prone to slagging in the burner area of ​​the furnace and contamination and clogging of high-temperature superheaters and high-temperature reheaters; circulating fluidized bed boilers are prone to coking on the bed surface and staining Dirt clogging problem

Although generally speaking, the operating period of circulating fluidized bed boilers burning coal with high alkali metal content is longer than that of pulverized coal boilers, and the blending ratio of circulating fluidized bed boilers is higher than that of pulverized coal boilers (generally 40% to 50% ), but due to the high price of the blended coal, the economy of unit operation has been significantly affected

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