A method for oxygen-increased combustion of pulverized coal mixed with biomass

Abstract

The invention belongs to the technical field of boiler combustion and discloses an oxygen-increase combustion method of a pulverized coal mixed biomass. According to the oxygen-increase combustion method, a mixture of the biomass and pulverized coal serves as fuel; pure oxygen is injected into a primary air pipeline and a secondary air pipeline to increase the concentration of the oxygen in a furnace hearth and promote stable and sufficient combustion of the fuel in the furnace hearth, wherein an air separation device is used for supplying two ways of pure oxygen; one way of pure oxygen and the air are mixed in the primary air pipeline to serve as oxygen-increase primary air to be fed into the furnace hearth, and the other way of pure oxygen and the air are mixed in the secondary air pipeline to serve as oxygen-increase secondary air to be fed into the furnace hearth; moreover, the heat value ratio of the biomass to the pulverized coal is 1:5-3:10. Through the oxygen-increase combustion method, by increasing the concentration of the oxygen in the furnace hearth, the combustion stability in the furnace is improved; meanwhile, the content of nitrogen in the furnace hearth is reduced,generation of NOx is reduced, smoke exhaust loss is reduced, and the combustion efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of boiler combustion, and more specifically relates to an oxygen-increased combustion method. Background technique [0002] Coal, oil, and natural gas, as the most important fossil energy sources at present, are all facing the problem of scarcity. And the excessive use of fossil energy has caused environmental problems such as the greenhouse effect, acid rain and various particle pollution. Biomass is a widely distributed, CO 2 "Zero-emission", low-pollution renewable energy has received extensive attention and research. Biomass is rich in variety and the available biomass energy is very considerable. According to statistics, photosynthesis can fix 2×10 11 t of carbon is about 10 times the total annual energy consumption in the world. In addition, biomass nitrogen and sulfur content are low (generally N content is 0.5% to 3%, S content is 0.1% to 1.5%) and ash content is also small, so SO emitted after c...

AI Technical Summary

Problems solved by technology

The cost of the two methods is lower for the transformation of existing power plants, but due to the low calorific value of biomass, the combustion characteristics are quite different from those of pulverized coal, which limits the ratio of calorific value of biomass to pulverized coal, otherwise it will lead to blending Combustion is very unstable, affecting the efficiency of the boiler

In the case of continuous operation of existing power plants, the proportion of calorific value of biomass generally used for blending is less than 5%, and the proportion of calorific value hardly exceeds 10%, so the utilization of biomass energy is limited

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