Combustion device for dewatering upgradation of lignite and reduction of nitrogen oxide emission and method thereof

Abstract

The invention discloses a combustion device for dewatering upgradation of lignite and reduction of nitrogen oxide emission. The combustion device comprises a pulverized coal drying device and a lignite combustion boiler, wherein the pulverized coal drying device consists of a pulverized coal cabin, a coal hopper, a drying furnace, a coke collection tank, a separator, a fan, a chilling machine, a first gas circulating pipeline, a second gas circulating pipeline and a primary air pipeline; and the lignite combustion boiler consists of a boiler hearth, an over fire air pipeline, a primary air and pulverized coal nozzle, a re-combustion fuel nozzle, an over fire air nozzle, a reheater, a high temperature convection superheater, a low temperature convection superheater, a coal economizer, an air preheater, a dust remover, an induced draught fan and a tail flue. The invention also discloses a combustion method for dewatering upgradation of lignite and reduction of nitrogen oxide emission. A fuel staged combustion technology is organically combined with a high temperature gas lignite drying technology, so that dewatering upgradation of lignite and reduction of nitrogen oxide NOx emission are guaranteed. The combustion device and the combustion method are simple and reliable, are convenient to manage, are suitable for pulverized coal boilers for combusting the lignite, particularly large and medium-sized power station boilers, and have broad application prospect.

Description

technical field [0001] The invention relates to the fields of lignite combustion and energy clean utilization, in particular to a combustion device and a combustion method for dehydrating and upgrading lignite and reducing nitrogen oxide emissions. Background technique [0002] my country is rich in lignite resources, accounting for about 13% of the country's total coal reserves, and has the characteristics of shallow burial, thick coal seams and large reserves. However, lignite has high moisture content, high volatile content of dry ash-free base, and low calorific value, so that the thermal efficiency of direct combustion is low, and the emission of greenhouse gases is large; at the same time, lignite has poor thermal stability, high reactivity, and is easy to weather and fragment. Oxidation spontaneous combustion, difficult to store and large-scale development and utilization. Therefore, dehydration and upgrading of lignite has become the key to the efficient development...

AI Technical Summary

Problems solved by technology

However, lignite has high moisture content, high volatile content of dry ash-free base, and low calorific value, so that the thermal efficiency of direct combustion is low, and the emission of greenhouse gases is large; at the same time, lignite has poor thermal stability, high reactivity, and is easy to weather and fragment. Oxidation spontaneous combustion, difficult to store and large-scale development and utilization

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