Power station boiler low-NOx cofiring system coupling semicoke and sludge blending combustion

Abstract

The invention discloses a power station boiler low-NOx cofiring system coupling semicoke and sludge blending combustion. The problems that the semicoke calorific value is high, but the ignition and burnout performance is poor, the NOx exhaust is large, the sludge water content is high, and the calorific value is low are solved. The system comprises a coal pulverizing system, a preheating system, asludge drying system, a burnout air nozzle and the like. By means of the characteristics that the sludge calorific value is low and the semicoke calorific value is high, the semicoke and the sludge are coupled. The system comprehensively considers optimization of the coal pulverizing system, multi-stage sludge drying, multi-stage utilization of smoke heat, semicoke and sludge mixed fuel preheating, utilization of air separation system cold energy, hearth partition combustion, burnout air arrangement, primary air and secondary air oxygenation treatment, and the coal-fired power plant boiler blending combustion semicoke and sludge low-NOx cofiring method is put forwards. Due to semicoke and sludge pretreatment and reasonable organized combustion, combustion stability inside a hearth is improved, NOx exhaust is reduced, and efficient and clean utilization of semicoke and large-scale harmless sludge disposal are achieved.

Description

technical field [0001] The invention belongs to the field of high-efficiency coal utilization and municipal solid waste treatment, in particular to a low NO power plant boiler coupled with semi-coke and sludge mixed combustion x Mixed combustion system. Background technique [0002] Semi-coke is a by-product obtained when low-rank coal such as peat and lignite is pyrolyzed to produce high value-added products such as gas. Compared with raw coal, it has the characteristics of low moisture content and high calorific value. The treatment of semi-coke is a non-negligible link in the process of efficient utilization of low-rank coal, and it is also an important part of the cascade utilization of coal resources in my country. In recent years, China's semi-coke industry has developed rapidly. In 2017, the annual production capacity of China's semi-coke has reached 70 million tons. A large amount of semi-coke needs to be efficiently utilized. Combusting power generation through po...

AI Technical Summary

Problems solved by technology

The traditional sludge incineration is to reduce the water content of the sludge through sludge drying equipment, and then put it into the sludge incinerator for incineration treatment. This process has a large area, complex system structure, low heat utilization rate and tail gas treatment. Problems such as high equipment cost

It is one of the new development directions to co-fire sludge and coal in power plant boilers to generate electricity. However, most of the current related projects use sludge direct co-firing technology. Due to the low calorific value and high water content of sludge, so Combustion is unstable, boiler output is reduced, and the proportion of sludge blended combustion is usually less than 5%, and the sludge treatment capacity is limited

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