A low NOx co-combustion system for power plant boilers coupled with semi-coke and sludge co-combustion

Abstract

The invention discloses a low NO power plant boiler coupled with semi-coke and sludge mixed combustion x Mixed combustion system. For semi-coke with high calorific value but poor ignition and burnout performance, NO x Problems such as high discharge, high moisture content and low calorific value of sludge, the system includes pulverizing system, preheating system, sludge drying system and burn-off air nozzle, etc. The characteristics of semi-coke and sludge are coupled and utilized. The system comprehensively considers the optimization of pulverizing system, multi-stage drying of sludge, multi-stage utilization of flue gas heat energy, preheating of mixed fuel of semi-coke and sludge, utilization of cold energy of air separation system, zone combustion of furnace, combustion The exhaust air arrangement, the oxygenation treatment of the primary air and the secondary air, proposed the low NO x Co-combustion method, through the pretreatment of semi-coke and sludge and reasonable organization of combustion, the stability of combustion in the furnace is improved and NOx is reduced x discharge, realizing the clean and efficient utilization of semi-coke and the large-scale harmless treatment of sludge.

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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