A flue gas recirculation boiler system burning fuel with high sodium and potassium content

Abstract

The invention discloses a flue gas recirculation boiler system burning fuel with high sodium and potassium contents. The flue gas recirculation boiler system comprises a hearth, a mixed smoke chamber arranged behind an outlet of the hearth, and a flue gas recirculation device, wherein a temperature control device is arranged at an outlet of the mixed smoke chamber; the outlet of the mixed smoke chamber is connected with a convection flue; the convection flue is internally provided with a plurality of stages of convection heating surfaces; one end of the flue gas recirculation device is communicated with a tail flue; and the other end of the flue gas recirculation device is communicated with the mixed smoke chamber by a flue gas mixing injector. With the adoption of the flue gas recirculation device, a part of low-temperature flue gas flowing through the tail flue flows back to the mixed smoke chamber; the low-temperature recirculated flue gas is used for cooling high-temperature flue gas; alkali metal compound steam in the flue gas is solidified in the mixed smoke chamber; and sublimated ash is prevented from being condensed on the convection heating surfaces to form condensate films, so that the problems of serious ash deposition and slagging on the high-temperature convection heating surfaces during burning of the fuel with the high sodium and potassium contents are solved fundamentally.

Description

Technical field [0001] The invention belongs to the field of thermal energy engineering research, and relates to a flue gas recirculation boiler system, in particular to a flue gas recirculation boiler system burning fuels with high sodium and potassium content. Background technique [0002] Energy is the material basis for the survival and development of human society, and has always been valued by countries all over the world. With the rapid development of our national economy in recent years, energy consumption has also increased day by day. However, my country is a country with energy shortage, so it is of great significance to realize the safe and efficient use of existing energy. [0003] my country has abundant fuel resources with high sodium and potassium content. The so-called high sodium and potassium content fuel refers to the equivalent of Na in the fuel. 2 O (equivalent Na 2 O=(Na 2 O+0.659K 2 O)×A d / 100, %; where: Na 2 O, K 2 O is the content of sodium oxide and pot...

AI Technical Summary

Problems solved by technology

The ash accumulation and slagging on the heating surface of the boiler will not only affect the output of the boiler and reduce the efficiency of the boiler, but also cause high-temperature corrosion on the tube wall of the heating surface, which will cause the tube metal to be in an over-temperature operating state and reduce the strength of the tube on the heating surface. When the ash accumulation and slagging are serious Occasionally, it will cause the boiler tube to burst, increase the maintenance workload or be forced to shut down the boiler, which poses a great threat to the safe and economical operation of the boiler

Therefore, the extensive and efficient utilization of Zhundong coal and other fuels with high sodium and potassium content in my country is greatly restricted.

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