Method for decreasing bonded slag and contamination during combustion of polybase metal fuels

Abstract

The invention discloses a method for decreasing bonded slag and contamination during combustion of polybase metal fuels. The method comprises the following steps of feeding mixed powder formed by mixing kaolin with a trace amount of limestone powder into a powder bin through a preparation system during combustion of the polybase metal fuels, then feeding the mixed powder into a pneumatic jet apparatus through pneumatic conveying, and jetting the mixed powder into a high-temperature area in a boiler through the pneumatic jet apparatus. The method utilizes special physic-chemical properties of the kaolin and the limestone powder. During the combustion of the polybase metal fuels, the bonded slag and contamination on the heated face of the boiler are decreased, and severe contamination situation caused when the polybase metal fuels are applied in the power station boiler is further improved.

Description

【Technical field】 [0001] The invention belongs to the field of thermal power generation, and in particular relates to a method for reducing slagging and pollution when burning polyalkali metal fuel. 【Background technique】 [0002] In the field of thermal power generation, with the discovery of the Zhundong coalfield in Xinjiang, the current shortage of coal resources has been greatly eased. The Zhundong Coalfield is a super-large coalfield that has been discovered in Xinjiang in recent years. The estimated reserves of coal resources are 390 billion tons. The pit mouth power station will use Zhundong coal as its main fuel. However, due to the fact that Zhundong coal is a polyalkali metal fuel, many power plants lack a deep understanding of its coal quality characteristics, resulting in serious slagging in the burner area of ​​the furnace and the contamination and blockage of some heating surfaces in the actual combustion process. In severe cases, it may even cause a pipe bu...

AI Technical Summary

Problems solved by technology

However, the process of removing sodium before fuel combustion is still immature, and the cost of removing sodium is relatively high compared with the cheap Zhundong open-pit coal, so it cannot be widely used at present.

[0009] Method 3) Reduce slagging and contamination by frequent soot blowing and special decoking agent, which can only be used as a temporary technical measure and should not be overly relied on

When burning multi-alkali metal fuel, due to the presence of bonded ash layer on the pipe wall of the heating surface, the complex chemical reaction between the ash layer and the pipe wall will lead to certain high-temperature corrosion, and frequent soot blowing will cause the ash layer to fall off. will accelerate the progress of corrosion

Simultaneous soot blowing causes frequent changes in pipe stress, which may shorten pipe life

In addition, in actual operation, the frequent use of the sootblower will also lead to an increase in the maintenance workload

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