A fuel staged gasification and low no x combustion boiler

Abstract

The invention relates to a fuel graded gasification and low NOx combustion boiler comprising a gasification hearth. A flame retardant coating is arranged on the inner wall of the gasification hearth,primary fuel nozzles and secondary fuel nozzles are arranged at the four corners of the gasification hearth in layered and spaced manners in a four-corner distribution tangential firing mode, the gasification hearth and a burning hearth are connected up and down through a diameter-changing smoke channel, the secondary fuel nozzles and SOFA nozzles are arranged on the wall face of the burning hearth in layered and spaced manners, an upper header is located at the top of the boiler, a lower header is annularly arranged on the exterior of the diameter-changing smoke channel, the inner wall of theburning hearth is provided with a water-cooling wall, and the upper header and the lower header communicate with each other. Primary coal powder gasifies to separate out a large amount of reducing gas in the gasification hearth with the excess air coefficient smaller than 1, secondary coal powder enters the gasification hearth to be mixed with the reducing gas to be gasified again, then the reducing gas enters the burning hearth, graded low-temperature low-oxygen combustion is carried out under the effects of secondary air and SOFA, and a boiler combustion device sequentially forms a main gasification zone, a secondary gasification zone, a reduction combustion zone and a burnout zone from bottom to top.

Description

Technical field [0001] The present invention relates to the fields of thermal energy and power engineering technology, combustion gasification and environmental protection technology, in particular to a fuel staging gasification and low NO X Burning boiler. Background technique [0002] NO X It is one of the culprits that have caused large-scale smog in recent years. In addition, NO X It will also induce a series of environmental problems such as photochemical smog and acid rain, and coal-fired boilers are my country’s NO X One of the most important sources of emissions. Due to the rapid economic growth, the nitrogen oxide emissions of coal-fired boilers in my country have been maintained at a relatively high level. X Emissions account for about the national NO X 35-40% of the total emissions pose a huge threat to our living environment. For this reason, the National Action Plan for Energy Conservation and Emission Reduction Upgrading and Retrofitting of Coal Power Plants propose...

AI Technical Summary

Problems solved by technology

Make the furnace form the main combustion zone, the reduction zone and the burnout zone. In the very small area near the burner nozzle where the pyrolysis process of the pulverized coal in the combustion system occurs, the pulverized coal enters the combustion zone for combustion before the pyrolysis is completely completed. Reducing gas CO, CH 4 、H 2 , HCN, NH 3 Wait less, NO X Emissions increase and reduced NO due to reduction of reducing gases X Less, can not fully reduce NO in flue gas X Content

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