CFB (circulating fluidized bed)-bunchy radiant boiler for reducing contamination of highly-alkali coal

Abstract

The invention discloses a CFB (circulating fluidized bed)-bunchy radiant boiler for reducing contamination of highly-alkali coal. The CFB-bunchy radiant boiler for reducing the contamination of the highly-alkali coal comprises a CFB boiler, a separating device and a bunchy radiant boiler, wherein passages communicated with the separating device are arranged at the upper end and the lower end of the side wall of the CFB boiler; the top of the separating device is communicated with a high-temperature flue; the high-temperature flue is communicated with the bunchy radiant boiler; the bunchy radiant boiler comprises a radiant heat exchanging part, a convective heat exchanging part and a shell; the radiant heat exchanging part is positioned in the middle of the shell; and the convective heat exchanging part is positioned between the radiant heat exchanging part and the shell. Through circulation of coal ash, the combustion contamination of the fluidized bed is avoided; through matching of a CFB boiler hearth and the bunchy radiant boiler, a convective heat exchanging surface is avoided in a 700-1100 DEG C section, so that the combustion contamination of the highly-alkali metal coal is greatly reduced; and a convective heating surface is omitted and a radiant boiler heating surface is adopted, so that required overheated steam can be obtained at an outlet of the radiant boiler.

Description

technical field [0001] The invention relates to a thermal gasification furnace of coal gasification technology, in particular to a CFB-beam radiation boiler for reducing contamination of high-alkaline coal. Background technique [0002] my country's power generation industry is dominated by thermal power generation, with thermal power installed capacity exceeding 70%. Thermal power coal mostly uses low-quality and low-grade coal. Slagging of boiler furnace water wall and contamination of convective heating surface are one of the important problems 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 and contamination may lead to major accidents such as boiler flameout, tube burst, and unplanned shutdown. [0003] In order to prevent various problems caused by slaggi...

AI Technical Summary

Problems solved by technology

The proportion of high-alkaline coal fired in the boiler should not exceed 30%. When the proportion of mixed fired coal increases, the convective heating surface will be seriously contaminated and ash will form a flue gas corridor, and the flue gas will cause leakage of the high-temperature reheater and high-temperature superheater.

Since high-alkaline coal is mostly used in pithead power stations in Xinjiang, the demand for coal blended with foreign coal is large. This method is often limited by transportation conditions, which greatly increases operating costs.

Images